extensions/renderer/dispatcher.cc

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "extensions/renderer/dispatcher.h"
   6
   7 #include "base/callback.h"
   8 #include "base/command_line.h"
   9 #include "base/debug/alias.h"
  10 #include "base/memory/scoped_ptr.h"
  11 #include "base/metrics/user_metrics_action.h"
  12 #include "base/strings/string_piece.h"
  13 #include "base/strings/string_split.h"
  14 #include "base/strings/string_util.h"
  15 #include "base/values.h"
  16 #include "content/public/common/content_switches.h"
  17 #include "content/public/common/url_constants.h"
  18 #include "content/public/renderer/render_thread.h"
  19 #include "content/public/renderer/render_view.h"
  20 #include "content/public/renderer/v8_value_converter.h"
  21 #include "extensions/common/api/messaging/message.h"
  22 #include "extensions/common/constants.h"
  23 #include "extensions/common/extension.h"
  24 #include "extensions/common/extension_api.h"
  25 #include "extensions/common/extension_messages.h"
  26 #include "extensions/common/extension_urls.h"
  27 #include "extensions/common/features/feature.h"
  28 #include "extensions/common/features/feature_provider.h"
  29 #include "extensions/common/manifest.h"
  30 #include "extensions/common/manifest_constants.h"
  31 #include "extensions/common/manifest_handlers/background_info.h"
  32 #include "extensions/common/manifest_handlers/externally_connectable.h"
  33 #include "extensions/common/manifest_handlers/sandboxed_page_info.h"
  34 #include "extensions/common/message_bundle.h"
  35 #include "extensions/common/permissions/permission_set.h"
  36 #include "extensions/common/permissions/permissions_data.h"
  37 #include "extensions/common/switches.h"
  38 #include "extensions/common/view_type.h"
  39 #include "extensions/renderer/api_activity_logger.h"
  40 #include "extensions/renderer/api_definitions_natives.h"
  41 #include "extensions/renderer/app_runtime_custom_bindings.h"
  42 #include "extensions/renderer/binding_generating_native_handler.h"
  43 #include "extensions/renderer/blob_native_handler.h"
  44 #include "extensions/renderer/content_watcher.h"
  45 #include "extensions/renderer/context_menus_custom_bindings.h"
  46 #include "extensions/renderer/css_native_handler.h"
  47 #include "extensions/renderer/dispatcher_delegate.h"
  48 #include "extensions/renderer/document_custom_bindings.h"
  49 #include "extensions/renderer/dom_activity_logger.h"
  50 #include "extensions/renderer/event_bindings.h"
  51 #include "extensions/renderer/extension_groups.h"
  52 #include "extensions/renderer/extension_helper.h"
  53 #include "extensions/renderer/extensions_renderer_client.h"
  54 #include "extensions/renderer/file_system_natives.h"
  55 #include "extensions/renderer/i18n_custom_bindings.h"
  56 #include "extensions/renderer/id_generator_custom_bindings.h"
  57 #include "extensions/renderer/lazy_background_page_native_handler.h"
  58 #include "extensions/renderer/logging_native_handler.h"
  59 #include "extensions/renderer/messaging_bindings.h"
  60 #include "extensions/renderer/module_system.h"
  61 #include "extensions/renderer/print_native_handler.h"
  62 #include "extensions/renderer/process_info_native_handler.h"
  63 #include "extensions/renderer/render_view_observer_natives.h"
  64 #include "extensions/renderer/request_sender.h"
  65 #include "extensions/renderer/runtime_custom_bindings.h"
  66 #include "extensions/renderer/safe_builtins.h"
  67 #include "extensions/renderer/script_context.h"
  68 #include "extensions/renderer/script_context_set.h"
  69 #include "extensions/renderer/send_request_natives.h"
  70 #include "extensions/renderer/set_icon_natives.h"
  71 #include "extensions/renderer/test_features_native_handler.h"
  72 #include "extensions/renderer/user_gestures_native_handler.h"
  73 #include "extensions/renderer/user_script_slave.h"
  74 #include "extensions/renderer/utils_native_handler.h"
  75 #include "extensions/renderer/v8_context_native_handler.h"
  76 #include "grit/common_resources.h"
  77 #include "grit/renderer_resources.h"
  78 #include "third_party/WebKit/public/platform/WebString.h"
  79 #include "third_party/WebKit/public/platform/WebURLRequest.h"
  80 #include "third_party/WebKit/public/web/WebCustomElement.h"
  81 #include "third_party/WebKit/public/web/WebDataSource.h"
  82 #include "third_party/WebKit/public/web/WebDocument.h"
  83 #include "third_party/WebKit/public/web/WebFrame.h"
  84 #include "third_party/WebKit/public/web/WebRuntimeFeatures.h"
  85 #include "third_party/WebKit/public/web/WebScopedUserGesture.h"
  86 #include "third_party/WebKit/public/web/WebSecurityPolicy.h"
  87 #include "third_party/WebKit/public/web/WebView.h"
  88 #include "ui/base/layout.h"
  89 #include "ui/base/resource/resource_bundle.h"
  90 #include "v8/include/v8.h"
  91
  92 using base::UserMetricsAction;
  93 using blink::WebDataSource;
  94 using blink::WebDocument;
  95 using blink::WebFrame;
  96 using blink::WebScopedUserGesture;
  97 using blink::WebSecurityPolicy;
  98 using blink::WebString;
  99 using blink::WebVector;
 100 using blink::WebView;
 101 using content::RenderThread;
 102 using content::RenderView;
 103
 104 namespace extensions {
 105
 106 namespace {
 107
 108 static const int64 kInitialExtensionIdleHandlerDelayMs = 5 * 1000;
 109 static const int64 kMaxExtensionIdleHandlerDelayMs = 5 * 60 * 1000;
 110 static const char kEventDispatchFunction[] = "dispatchEvent";
 111 static const char kOnSuspendEvent[] = "runtime.onSuspend";
 112 static const char kOnSuspendCanceledEvent[] = "runtime.onSuspendCanceled";
 113
 114 // Returns the global value for "chrome" from |context|. If one doesn't exist
 115 // creates a new object for it.
 116 //
 117 // Note that this isn't necessarily an object, since webpages can write, for
 118 // example, "window.chrome = true".
 119 v8::Handle<v8::Value> GetOrCreateChrome(ScriptContext* context) {
 120   v8::Handle<v8::String> chrome_string(
 121       v8::String::NewFromUtf8(context->isolate(), "chrome"));
 122   v8::Handle<v8::Object> global(context->v8_context()->Global());
 123   v8::Handle<v8::Value> chrome(global->Get(chrome_string));
 124   if (chrome->IsUndefined()) {
 125     chrome = v8::Object::New(context->isolate());
 126     global->Set(chrome_string, chrome);
 127   }
 128   return chrome;
 129 }
 130
 131 // Returns |value| cast to an object if possible, else an empty handle.
 132 v8::Handle<v8::Object> AsObjectOrEmpty(v8::Handle<v8::Value> value) {
 133   return value->IsObject() ? value.As<v8::Object>() : v8::Handle<v8::Object>();
 134 }
 135
 136 // Calls a method |method_name| in a module |module_name| belonging to the
 137 // module system from |context|. Intended as a callback target from
 138 // ScriptContextSet::ForEach.
 139 void CallModuleMethod(const std::string& module_name,
 140                       const std::string& method_name,
 141                       const base::ListValue* args,
 142                       ScriptContext* context) {
 143   v8::HandleScope handle_scope(context->isolate());
 144   v8::Context::Scope context_scope(context->v8_context());
 145
 146   scoped_ptr<content::V8ValueConverter> converter(
 147       content::V8ValueConverter::create());
 148
 149   std::vector<v8::Handle<v8::Value> > arguments;
 150   for (base::ListValue::const_iterator it = args->begin(); it != args->end();
 151        ++it) {
 152     arguments.push_back(converter->ToV8Value(*it, context->v8_context()));
 153   }
 154
 155   context->module_system()->CallModuleMethod(
 156       module_name, method_name, &arguments);
 157 }
 158
 159 // This handles the "chrome." root API object in script contexts.
 160 class ChromeNativeHandler : public ObjectBackedNativeHandler {
 161  public:
 162   explicit ChromeNativeHandler(ScriptContext* context)
 163       : ObjectBackedNativeHandler(context) {
 164     RouteFunction(
 165         "GetChrome",
 166         base::Bind(&ChromeNativeHandler::GetChrome, base::Unretained(this)));
 167   }
 168
 169   void GetChrome(const v8::FunctionCallbackInfo<v8::Value>& args) {
 170     args.GetReturnValue().Set(GetOrCreateChrome(context()));
 171   }
 172 };
 173
 174 }  // namespace
 175
 176 Dispatcher::Dispatcher(DispatcherDelegate* delegate)
 177     : delegate_(delegate),
 178       content_watcher_(new ContentWatcher()),
 179       source_map_(&ResourceBundle::GetSharedInstance()),
 180       v8_schema_registry_(new V8SchemaRegistry),
 181       is_webkit_initialized_(false) {
 182   const CommandLine& command_line = *(CommandLine::ForCurrentProcess());
 183   is_extension_process_ =
 184       command_line.HasSwitch(extensions::switches::kExtensionProcess) ||
 185       command_line.HasSwitch(::switches::kSingleProcess);
 186
 187   if (is_extension_process_) {
 188     RenderThread::Get()->SetIdleNotificationDelayInMs(
 189         kInitialExtensionIdleHandlerDelayMs);
 190   }
 191
 192   RenderThread::Get()->RegisterExtension(SafeBuiltins::CreateV8Extension());
 193
 194   user_script_slave_.reset(new UserScriptSlave(&extensions_));
 195   request_sender_.reset(new RequestSender(this));
 196   PopulateSourceMap();
 197 }
 198
 199 Dispatcher::~Dispatcher() {
 200 }
 201
 202 bool Dispatcher::IsExtensionActive(const std::string& extension_id) const {
 203   bool is_active =
 204       active_extension_ids_.find(extension_id) != active_extension_ids_.end();
 205   if (is_active)
 206     CHECK(extensions_.Contains(extension_id));
 207   return is_active;
 208 }
 209
 210 std::string Dispatcher::GetExtensionID(const WebFrame* frame, int world_id) {
 211   if (world_id != 0) {
 212     // Isolated worlds (content script).
 213     return user_script_slave_->GetExtensionIdForIsolatedWorld(world_id);
 214   }
 215
 216   // TODO(kalman): Delete this check.
 217   if (frame->document().securityOrigin().isUnique())
 218     return std::string();
 219
 220   // Extension pages (chrome-extension:// URLs).
 221   GURL frame_url = ScriptContext::GetDataSourceURLForFrame(frame);
 222   return extensions_.GetExtensionOrAppIDByURL(frame_url);
 223 }
 224
 225 void Dispatcher::DidCreateScriptContext(
 226     WebFrame* frame,
 227     const v8::Handle<v8::Context>& v8_context,
 228     int extension_group,
 229     int world_id) {
 230 #if !defined(ENABLE_EXTENSIONS)
 231   return;
 232 #endif
 233
 234   std::string extension_id = GetExtensionID(frame, world_id);
 235
 236   const Extension* extension = extensions_.GetByID(extension_id);
 237   if (!extension && !extension_id.empty()) {
 238     // There are conditions where despite a context being associated with an
 239     // extension, no extension actually gets found.  Ignore "invalid" because
 240     // CSP blocks extension page loading by switching the extension ID to
 241     // "invalid". This isn't interesting.
 242     if (extension_id != "invalid") {
 243       LOG(ERROR) << "Extension \"" << extension_id << "\" not found";
 244       RenderThread::Get()->RecordAction(
 245           UserMetricsAction("ExtensionNotFound_ED"));
 246     }
 247
 248     extension_id = "";
 249   }
 250
 251   Feature::Context context_type =
 252       ClassifyJavaScriptContext(extension,
 253                                 extension_group,
 254                                 ScriptContext::GetDataSourceURLForFrame(frame),
 255                                 frame->document().securityOrigin());
 256
 257   ScriptContext* context =
 258       delegate_->CreateScriptContext(v8_context, frame, extension, context_type)
 259           .release();
 260   script_context_set_.Add(context);
 261
 262   if (extension) {
 263     InitOriginPermissions(extension, context_type);
 264   }
 265
 266   {
 267     scoped_ptr<ModuleSystem> module_system(
 268         new ModuleSystem(context, &source_map_));
 269     context->set_module_system(module_system.Pass());
 270   }
 271   ModuleSystem* module_system = context->module_system();
 272
 273   // Enable natives in startup.
 274   ModuleSystem::NativesEnabledScope natives_enabled_scope(module_system);
 275
 276   RegisterNativeHandlers(module_system, context);
 277
 278   // chrome.Event is part of the public API (although undocumented). Make it
 279   // lazily evalulate to Event from event_bindings.js. For extensions only
 280   // though, not all webpages!
 281   if (context->extension()) {
 282     v8::Handle<v8::Object> chrome = AsObjectOrEmpty(GetOrCreateChrome(context));
 283     if (!chrome.IsEmpty())
 284       module_system->SetLazyField(chrome, "Event", kEventBindings, "Event");
 285   }
 286
 287   UpdateBindingsForContext(context);
 288
 289   bool is_within_platform_app = IsWithinPlatformApp();
 290   // Inject custom JS into the platform app context.
 291   if (is_within_platform_app) {
 292     module_system->Require("platformApp");
 293   }
 294
 295   delegate_->RequireAdditionalModules(
 296       module_system, extension, context_type, is_within_platform_app);
 297
 298   VLOG(1) << "Num tracked contexts: " << script_context_set_.size();
 299 }
 300
 301 void Dispatcher::WillReleaseScriptContext(
 302     WebFrame* frame,
 303     const v8::Handle<v8::Context>& v8_context,
 304     int world_id) {
 305   ScriptContext* context = script_context_set_.GetByV8Context(v8_context);
 306   if (!context)
 307     return;
 308
 309   context->DispatchOnUnloadEvent();
 310   // TODO(kalman): add an invalidation observer interface to ScriptContext.
 311   request_sender_->InvalidateSource(context);
 312
 313   script_context_set_.Remove(context);
 314   VLOG(1) << "Num tracked contexts: " << script_context_set_.size();
 315 }
 316
 317 void Dispatcher::DidCreateDocumentElement(blink::WebFrame* frame) {
 318   if (IsWithinPlatformApp()) {
 319     // WebKit doesn't let us define an additional user agent stylesheet, so we
 320     // insert the default platform app stylesheet into all documents that are
 321     // loaded in each app.
 322     std::string stylesheet = ResourceBundle::GetSharedInstance()
 323                                  .GetRawDataResource(IDR_PLATFORM_APP_CSS)
 324                                  .as_string();
 325     ReplaceFirstSubstringAfterOffset(
 326         &stylesheet, 0, "$FONTFAMILY", system_font_family_);
 327     ReplaceFirstSubstringAfterOffset(
 328         &stylesheet, 0, "$FONTSIZE", system_font_size_);
 329     frame->document().insertStyleSheet(WebString::fromUTF8(stylesheet));
 330   }
 331
 332   content_watcher_->DidCreateDocumentElement(frame);
 333 }
 334
 335 void Dispatcher::DidMatchCSS(
 336     blink::WebFrame* frame,
 337     const blink::WebVector<blink::WebString>& newly_matching_selectors,
 338     const blink::WebVector<blink::WebString>& stopped_matching_selectors) {
 339   content_watcher_->DidMatchCSS(
 340       frame, newly_matching_selectors, stopped_matching_selectors);
 341 }
 342
 343 void Dispatcher::OnExtensionResponse(int request_id,
 344                                      bool success,
 345                                      const base::ListValue& response,
 346                                      const std::string& error) {
 347   request_sender_->HandleResponse(request_id, success, response, error);
 348 }
 349
 350 bool Dispatcher::CheckContextAccessToExtensionAPI(
 351     const std::string& function_name,
 352     ScriptContext* context) const {
 353   if (!context) {
 354     DLOG(ERROR) << "Not in a v8::Context";
 355     return false;
 356   }
 357
 358   if (!context->extension()) {
 359     context->isolate()->ThrowException(v8::Exception::Error(
 360         v8::String::NewFromUtf8(context->isolate(), "Not in an extension.")));
 361     return false;
 362   }
 363
 364   // Theoretically we could end up with bindings being injected into sandboxed
 365   // frames, for example content scripts. Don't let them execute API functions.
 366   blink::WebFrame* frame = context->web_frame();
 367   if (IsSandboxedPage(ScriptContext::GetDataSourceURLForFrame(frame))) {
 368     static const char kMessage[] =
 369         "%s cannot be used within a sandboxed frame.";
 370     std::string error_msg = base::StringPrintf(kMessage, function_name.c_str());
 371     context->isolate()->ThrowException(v8::Exception::Error(
 372         v8::String::NewFromUtf8(context->isolate(), error_msg.c_str())));
 373     return false;
 374   }
 375
 376   Feature::Availability availability = context->GetAvailability(function_name);
 377   if (!availability.is_available()) {
 378     context->isolate()->ThrowException(
 379         v8::Exception::Error(v8::String::NewFromUtf8(
 380             context->isolate(), availability.message().c_str())));
 381   }
 382
 383   return availability.is_available();
 384 }
 385
 386 void Dispatcher::DispatchEvent(const std::string& extension_id,
 387                                const std::string& event_name) const {
 388   base::ListValue args;
 389   args.Set(0, new base::StringValue(event_name));
 390   args.Set(1, new base::ListValue());
 391
 392   // Needed for Windows compilation, since kEventBindings is declared extern.
 393   const char* local_event_bindings = kEventBindings;
 394   script_context_set_.ForEach(extension_id,
 395                               NULL,  // all render views
 396                               base::Bind(&CallModuleMethod,
 397                                          local_event_bindings,
 398                                          kEventDispatchFunction,
 399                                          &args));
 400 }
 401
 402 void Dispatcher::InvokeModuleSystemMethod(content::RenderView* render_view,
 403                                           const std::string& extension_id,
 404                                           const std::string& module_name,
 405                                           const std::string& function_name,
 406                                           const base::ListValue& args,
 407                                           bool user_gesture) {
 408   scoped_ptr<WebScopedUserGesture> web_user_gesture;
 409   if (user_gesture)
 410     web_user_gesture.reset(new WebScopedUserGesture);
 411
 412   script_context_set_.ForEach(
 413       extension_id,
 414       render_view,
 415       base::Bind(&CallModuleMethod, module_name, function_name, &args));
 416
 417   // Reset the idle handler each time there's any activity like event or message
 418   // dispatch, for which Invoke is the chokepoint.
 419   if (is_extension_process_) {
 420     RenderThread::Get()->ScheduleIdleHandler(
 421         kInitialExtensionIdleHandlerDelayMs);
 422   }
 423
 424   // Tell the browser process when an event has been dispatched with a lazy
 425   // background page active.
 426   const Extension* extension = extensions_.GetByID(extension_id);
 427   if (extension && BackgroundInfo::HasLazyBackgroundPage(extension) &&
 428       module_name == kEventBindings &&
 429       function_name == kEventDispatchFunction) {
 430     RenderView* background_view =
 431         ExtensionHelper::GetBackgroundPage(extension_id);
 432     if (background_view) {
 433       background_view->Send(
 434           new ExtensionHostMsg_EventAck(background_view->GetRoutingID()));
 435     }
 436   }
 437 }
 438
 439 void Dispatcher::ClearPortData(int port_id) {
 440   // Only the target port side has entries in |port_to_tab_id_map_|. If
 441   // |port_id| is a source port, std::map::erase() will just silently fail
 442   // here as a no-op.
 443   port_to_tab_id_map_.erase(port_id);
 444 }
 445
 446 bool Dispatcher::OnControlMessageReceived(const IPC::Message& message) {
 447   bool handled = true;
 448   IPC_BEGIN_MESSAGE_MAP(Dispatcher, message)
 449   IPC_MESSAGE_HANDLER(ExtensionMsg_ActivateExtension, OnActivateExtension)
 450   IPC_MESSAGE_HANDLER(ExtensionMsg_CancelSuspend, OnCancelSuspend)
 451   IPC_MESSAGE_HANDLER(ExtensionMsg_ClearTabSpecificPermissions,
 452                       OnClearTabSpecificPermissions)
 453   IPC_MESSAGE_HANDLER(ExtensionMsg_DeliverMessage, OnDeliverMessage)
 454   IPC_MESSAGE_HANDLER(ExtensionMsg_DispatchOnConnect, OnDispatchOnConnect)
 455   IPC_MESSAGE_HANDLER(ExtensionMsg_DispatchOnDisconnect, OnDispatchOnDisconnect)
 456   IPC_MESSAGE_HANDLER(ExtensionMsg_Loaded, OnLoaded)
 457   IPC_MESSAGE_HANDLER(ExtensionMsg_MessageInvoke, OnMessageInvoke)
 458   IPC_MESSAGE_HANDLER(ExtensionMsg_SetChannel, OnSetChannel)
 459   IPC_MESSAGE_HANDLER(ExtensionMsg_SetFunctionNames, OnSetFunctionNames)
 460   IPC_MESSAGE_HANDLER(ExtensionMsg_SetScriptingWhitelist,
 461                       OnSetScriptingWhitelist)
 462   IPC_MESSAGE_HANDLER(ExtensionMsg_SetSystemFont, OnSetSystemFont)
 463   IPC_MESSAGE_HANDLER(ExtensionMsg_ShouldSuspend, OnShouldSuspend)
 464   IPC_MESSAGE_HANDLER(ExtensionMsg_Suspend, OnSuspend)
 465   IPC_MESSAGE_HANDLER(ExtensionMsg_Unloaded, OnUnloaded)
 466   IPC_MESSAGE_HANDLER(ExtensionMsg_UpdatePermissions, OnUpdatePermissions)
 467   IPC_MESSAGE_HANDLER(ExtensionMsg_UpdateTabSpecificPermissions,
 468                       OnUpdateTabSpecificPermissions)
 469   IPC_MESSAGE_HANDLER(ExtensionMsg_UpdateUserScripts, OnUpdateUserScripts)
 470   IPC_MESSAGE_HANDLER(ExtensionMsg_UsingWebRequestAPI, OnUsingWebRequestAPI)
 471   IPC_MESSAGE_FORWARD(ExtensionMsg_WatchPages,
 472                       content_watcher_.get(),
 473                       ContentWatcher::OnWatchPages)
 474   IPC_MESSAGE_UNHANDLED(handled = false)
 475   IPC_END_MESSAGE_MAP()
 476
 477   return handled;
 478 }
 479
 480 void Dispatcher::WebKitInitialized() {
 481   // For extensions, we want to ensure we call the IdleHandler every so often,
 482   // even if the extension keeps up activity.
 483   if (is_extension_process_) {
 484     forced_idle_timer_.reset(new base::RepeatingTimer<content::RenderThread>);
 485     forced_idle_timer_->Start(
 486         FROM_HERE,
 487         base::TimeDelta::FromMilliseconds(kMaxExtensionIdleHandlerDelayMs),
 488         RenderThread::Get(),
 489         &RenderThread::IdleHandler);
 490   }
 491
 492   // Initialize host permissions for any extensions that were activated before
 493   // WebKit was initialized.
 494   for (std::set<std::string>::iterator iter = active_extension_ids_.begin();
 495        iter != active_extension_ids_.end();
 496        ++iter) {
 497     const Extension* extension = extensions_.GetByID(*iter);
 498     CHECK(extension);
 499   }
 500
 501   EnableCustomElementWhiteList();
 502
 503   is_webkit_initialized_ = true;
 504 }
 505
 506 void Dispatcher::IdleNotification() {
 507   if (is_extension_process_) {
 508     // Dampen the forced delay as well if the extension stays idle for long
 509     // periods of time.
 510     int64 forced_delay_ms =
 511         std::max(RenderThread::Get()->GetIdleNotificationDelayInMs(),
 512                  kMaxExtensionIdleHandlerDelayMs);
 513     forced_idle_timer_->Stop();
 514     forced_idle_timer_->Start(
 515         FROM_HERE,
 516         base::TimeDelta::FromMilliseconds(forced_delay_ms),
 517         RenderThread::Get(),
 518         &RenderThread::IdleHandler);
 519   }
 520 }
 521
 522 void Dispatcher::OnRenderProcessShutdown() {
 523   v8_schema_registry_.reset();
 524   forced_idle_timer_.reset();
 525 }
 526
 527 void Dispatcher::OnActivateExtension(const std::string& extension_id) {
 528   const Extension* extension = extensions_.GetByID(extension_id);
 529   if (!extension) {
 530     // Extension was activated but was never loaded. This probably means that
 531     // the renderer failed to load it (or the browser failed to tell us when it
 532     // did). Failures shouldn't happen, but instead of crashing there (which
 533     // executes on all renderers) be conservative and only crash in the renderer
 534     // of the extension which failed to load; this one.
 535     std::string& error = extension_load_errors_[extension_id];
 536     char minidump[256];
 537     base::debug::Alias(&minidump);
 538     base::snprintf(minidump,
 539                    arraysize(minidump),
 540                    "e::dispatcher:%s:%s",
 541                    extension_id.c_str(),
 542                    error.c_str());
 543     CHECK(extension) << extension_id << " was never loaded: " << error;
 544   }
 545
 546   active_extension_ids_.insert(extension_id);
 547
 548   // This is called when starting a new extension page, so start the idle
 549   // handler ticking.
 550   RenderThread::Get()->ScheduleIdleHandler(kInitialExtensionIdleHandlerDelayMs);
 551
 552   if (is_webkit_initialized_) {
 553     extensions::DOMActivityLogger::AttachToWorld(
 554         extensions::DOMActivityLogger::kMainWorldId, extension_id);
 555   }
 556
 557   UpdateActiveExtensions();
 558 }
 559
 560 void Dispatcher::OnCancelSuspend(const std::string& extension_id) {
 561   DispatchEvent(extension_id, kOnSuspendCanceledEvent);
 562 }
 563
 564 void Dispatcher::OnClearTabSpecificPermissions(
 565     int tab_id,
 566     const std::vector<std::string>& extension_ids) {
 567   delegate_->ClearTabSpecificPermissions(this, tab_id, extension_ids);
 568 }
 569
 570 void Dispatcher::OnDeliverMessage(int target_port_id, const Message& message) {
 571   scoped_ptr<RequestSender::ScopedTabID> scoped_tab_id;
 572   std::map<int, int>::const_iterator it =
 573       port_to_tab_id_map_.find(target_port_id);
 574   if (it != port_to_tab_id_map_.end()) {
 575     scoped_tab_id.reset(
 576         new RequestSender::ScopedTabID(request_sender(), it->second));
 577   }
 578
 579   MessagingBindings::DeliverMessage(script_context_set_.GetAll(),
 580                                     target_port_id,
 581                                     message,
 582                                     NULL);  // All render views.
 583 }
 584
 585 void Dispatcher::OnDispatchOnConnect(
 586     int target_port_id,
 587     const std::string& channel_name,
 588     const base::DictionaryValue& source_tab,
 589     const ExtensionMsg_ExternalConnectionInfo& info,
 590     const std::string& tls_channel_id) {
 591   DCHECK(!ContainsKey(port_to_tab_id_map_, target_port_id));
 592   DCHECK_EQ(1, target_port_id % 2);  // target renderer ports have odd IDs.
 593   int sender_tab_id = -1;
 594   source_tab.GetInteger("id", &sender_tab_id);
 595   port_to_tab_id_map_[target_port_id] = sender_tab_id;
 596
 597   MessagingBindings::DispatchOnConnect(script_context_set_.GetAll(),
 598                                        target_port_id,
 599                                        channel_name,
 600                                        source_tab,
 601                                        info.source_id,
 602                                        info.target_id,
 603                                        info.source_url,
 604                                        tls_channel_id,
 605                                        NULL);  // All render views.
 606 }
 607
 608 void Dispatcher::OnDispatchOnDisconnect(int port_id,
 609                                         const std::string& error_message) {
 610   MessagingBindings::DispatchOnDisconnect(script_context_set_.GetAll(),
 611                                           port_id,
 612                                           error_message,
 613                                           NULL);  // All render views.
 614 }
 615
 616 void Dispatcher::OnLoaded(
 617     const std::vector<ExtensionMsg_Loaded_Params>& loaded_extensions) {
 618   std::vector<ExtensionMsg_Loaded_Params>::const_iterator i;
 619   for (i = loaded_extensions.begin(); i != loaded_extensions.end(); ++i) {
 620     std::string error;
 621     scoped_refptr<const Extension> extension = i->ConvertToExtension(&error);
 622     if (!extension.get()) {
 623       extension_load_errors_[i->id] = error;
 624       continue;
 625     }
 626     OnLoadedInternal(extension);
 627   }
 628   // Update the available bindings for all contexts. These may have changed if
 629   // an externally_connectable extension was loaded that can connect to an
 630   // open webpage.
 631   UpdateBindings("");
 632 }
 633
 634 void Dispatcher::OnLoadedInternal(scoped_refptr<const Extension> extension) {
 635   extensions_.Insert(extension);
 636 }
 637
 638 void Dispatcher::OnMessageInvoke(const std::string& extension_id,
 639                                  const std::string& module_name,
 640                                  const std::string& function_name,
 641                                  const base::ListValue& args,
 642                                  bool user_gesture) {
 643   InvokeModuleSystemMethod(
 644       NULL, extension_id, module_name, function_name, args, user_gesture);
 645 }
 646
 647 void Dispatcher::OnSetChannel(int channel) {
 648   delegate_->SetChannel(channel);
 649 }
 650
 651 void Dispatcher::OnSetFunctionNames(const std::vector<std::string>& names) {
 652   function_names_.clear();
 653   for (size_t i = 0; i < names.size(); ++i)
 654     function_names_.insert(names[i]);
 655 }
 656
 657 void Dispatcher::OnSetScriptingWhitelist(
 658     const ExtensionsClient::ScriptingWhitelist& extension_ids) {
 659   ExtensionsClient::Get()->SetScriptingWhitelist(extension_ids);
 660 }
 661
 662 void Dispatcher::OnSetSystemFont(const std::string& font_family,
 663                                  const std::string& font_size) {
 664   system_font_family_ = font_family;
 665   system_font_size_ = font_size;
 666 }
 667
 668 void Dispatcher::OnShouldSuspend(const std::string& extension_id,
 669                                  int sequence_id) {
 670   RenderThread::Get()->Send(
 671       new ExtensionHostMsg_ShouldSuspendAck(extension_id, sequence_id));
 672 }
 673
 674 void Dispatcher::OnSuspend(const std::string& extension_id) {
 675   // Dispatch the suspend event. This doesn't go through the standard event
 676   // dispatch machinery because it requires special handling. We need to let
 677   // the browser know when we are starting and stopping the event dispatch, so
 678   // that it still considers the extension idle despite any activity the suspend
 679   // event creates.
 680   DispatchEvent(extension_id, kOnSuspendEvent);
 681   RenderThread::Get()->Send(new ExtensionHostMsg_SuspendAck(extension_id));
 682 }
 683
 684 void Dispatcher::OnUnloaded(const std::string& id) {
 685   extensions_.Remove(id);
 686   active_extension_ids_.erase(id);
 687
 688   // If the extension is later reloaded with a different set of permissions,
 689   // we'd like it to get a new isolated world ID, so that it can pick up the
 690   // changed origin whitelist.
 691   user_script_slave_->RemoveIsolatedWorld(id);
 692
 693   // Invalidate all of the contexts that were removed.
 694   // TODO(kalman): add an invalidation observer interface to ScriptContext.
 695   ScriptContextSet::ContextSet removed_contexts =
 696       script_context_set_.OnExtensionUnloaded(id);
 697   for (ScriptContextSet::ContextSet::iterator it = removed_contexts.begin();
 698        it != removed_contexts.end();
 699        ++it) {
 700     request_sender_->InvalidateSource(*it);
 701   }
 702
 703   // Update the available bindings for the remaining contexts. These may have
 704   // changed if an externally_connectable extension is unloaded and a webpage
 705   // is no longer accessible.
 706   UpdateBindings("");
 707
 708   // Invalidates the messages map for the extension in case the extension is
 709   // reloaded with a new messages map.
 710   EraseL10nMessagesMap(id);
 711
 712   // We don't do anything with existing platform-app stylesheets. They will
 713   // stay resident, but the URL pattern corresponding to the unloaded
 714   // extension's URL just won't match anything anymore.
 715 }
 716
 717 void Dispatcher::OnUpdatePermissions(
 718     const ExtensionMsg_UpdatePermissions_Params& params) {
 719   int reason_id = params.reason_id;
 720   const std::string& extension_id = params.extension_id;
 721   const APIPermissionSet& apis = params.apis;
 722   const ManifestPermissionSet& manifest_permissions =
 723       params.manifest_permissions;
 724   const URLPatternSet& explicit_hosts = params.explicit_hosts;
 725   const URLPatternSet& scriptable_hosts = params.scriptable_hosts;
 726
 727   const Extension* extension = extensions_.GetByID(extension_id);
 728   if (!extension)
 729     return;
 730
 731   scoped_refptr<const PermissionSet> delta = new PermissionSet(
 732       apis, manifest_permissions, explicit_hosts, scriptable_hosts);
 733   scoped_refptr<const PermissionSet> old_active =
 734       extension->GetActivePermissions();
 735   UpdatedExtensionPermissionsInfo::Reason reason =
 736       static_cast<UpdatedExtensionPermissionsInfo::Reason>(reason_id);
 737
 738   const PermissionSet* new_active = NULL;
 739   switch (reason) {
 740     case UpdatedExtensionPermissionsInfo::ADDED:
 741       new_active = PermissionSet::CreateUnion(old_active.get(), delta.get());
 742       break;
 743     case UpdatedExtensionPermissionsInfo::REMOVED:
 744       new_active =
 745           PermissionSet::CreateDifference(old_active.get(), delta.get());
 746       break;
 747   }
 748
 749   PermissionsData::SetActivePermissions(extension, new_active);
 750   UpdateOriginPermissions(reason, extension, explicit_hosts);
 751   UpdateBindings(extension->id());
 752 }
 753
 754 void Dispatcher::OnUpdateTabSpecificPermissions(
 755     int page_id,
 756     int tab_id,
 757     const std::string& extension_id,
 758     const URLPatternSet& origin_set) {
 759   delegate_->UpdateTabSpecificPermissions(
 760       this, page_id, tab_id, extension_id, origin_set);
 761 }
 762
 763 void Dispatcher::OnUpdateUserScripts(base::SharedMemoryHandle scripts) {
 764   DCHECK(base::SharedMemory::IsHandleValid(scripts)) << "Bad scripts handle";
 765   user_script_slave_->UpdateScripts(scripts);
 766   UpdateActiveExtensions();
 767 }
 768
 769 void Dispatcher::OnUsingWebRequestAPI(bool adblock,
 770                                       bool adblock_plus,
 771                                       bool other_webrequest) {
 772   delegate_->HandleWebRequestAPIUsage(adblock, adblock_plus, other_webrequest);
 773 }
 774
 775 void Dispatcher::UpdateActiveExtensions() {
 776   std::set<std::string> active_extensions = active_extension_ids_;
 777   user_script_slave_->GetActiveExtensions(&active_extensions);
 778   delegate_->OnActiveExtensionsUpdated(active_extensions);
 779 }
 780
 781 void Dispatcher::InitOriginPermissions(const Extension* extension,
 782                                        Feature::Context context_type) {
 783   delegate_->InitOriginPermissions(extension, context_type);
 784   UpdateOriginPermissions(
 785       UpdatedExtensionPermissionsInfo::ADDED,
 786       extension,
 787       PermissionsData::GetEffectiveHostPermissions(extension));
 788 }
 789
 790 void Dispatcher::UpdateOriginPermissions(
 791     UpdatedExtensionPermissionsInfo::Reason reason,
 792     const Extension* extension,
 793     const URLPatternSet& origins) {
 794   for (URLPatternSet::const_iterator i = origins.begin(); i != origins.end();
 795        ++i) {
 796     const char* schemes[] = {
 797         content::kHttpScheme,     content::kHttpsScheme, content::kFileScheme,
 798         content::kChromeUIScheme, content::kFtpScheme,
 799     };
 800     for (size_t j = 0; j < arraysize(schemes); ++j) {
 801       if (i->MatchesScheme(schemes[j])) {
 802         ((reason == UpdatedExtensionPermissionsInfo::REMOVED)
 803              ? WebSecurityPolicy::removeOriginAccessWhitelistEntry
 804              : WebSecurityPolicy::addOriginAccessWhitelistEntry)(
 805             extension->url(),
 806             WebString::fromUTF8(schemes[j]),
 807             WebString::fromUTF8(i->host()),
 808             i->match_subdomains());
 809       }
 810     }
 811   }
 812 }
 813
 814 void Dispatcher::EnableCustomElementWhiteList() {
 815   blink::WebCustomElement::addEmbedderCustomElementName("webview");
 816   // TODO(fsamuel): Add <adview> to the whitelist once it has been converted
 817   // into a custom element.
 818   blink::WebCustomElement::addEmbedderCustomElementName("browser-plugin");
 819 }
 820
 821 void Dispatcher::UpdateBindings(const std::string& extension_id) {
 822   script_context_set().ForEach(extension_id,
 823                                NULL,  // all render views
 824                                base::Bind(&Dispatcher::UpdateBindingsForContext,
 825                                           base::Unretained(this)));
 826 }
 827
 828 void Dispatcher::UpdateBindingsForContext(ScriptContext* context) {
 829   v8::HandleScope handle_scope(context->isolate());
 830   v8::Context::Scope context_scope(context->v8_context());
 831
 832   // TODO(kalman): Make the bindings registration have zero overhead then run
 833   // the same code regardless of context type.
 834   switch (context->context_type()) {
 835     case Feature::UNSPECIFIED_CONTEXT:
 836     case Feature::WEB_PAGE_CONTEXT:
 837     case Feature::BLESSED_WEB_PAGE_CONTEXT: {
 838       // Web page context; it's too expensive to run the full bindings code.
 839       // Hard-code that the app and webstore APIs are available...
 840       RegisterBinding("app", context);
 841       RegisterBinding("webstore", context);
 842
 843       // ... and that the runtime API might be available if any extension can
 844       // connect to it.
 845       bool runtime_is_available = false;
 846       for (ExtensionSet::const_iterator it = extensions_.begin();
 847            it != extensions_.end();
 848            ++it) {
 849         ExternallyConnectableInfo* info =
 850             static_cast<ExternallyConnectableInfo*>(
 851                 (*it)->GetManifestData(manifest_keys::kExternallyConnectable));
 852         if (info && info->matches.MatchesURL(context->GetURL())) {
 853           runtime_is_available = true;
 854           break;
 855         }
 856       }
 857       if (runtime_is_available)
 858         RegisterBinding("runtime", context);
 859       break;
 860     }
 861
 862     case Feature::BLESSED_EXTENSION_CONTEXT:
 863     case Feature::UNBLESSED_EXTENSION_CONTEXT:
 864     case Feature::CONTENT_SCRIPT_CONTEXT: {
 865       // Extension context; iterate through all the APIs and bind the available
 866       // ones.
 867       FeatureProvider* api_feature_provider = FeatureProvider::GetAPIFeatures();
 868       const std::vector<std::string>& apis =
 869           api_feature_provider->GetAllFeatureNames();
 870       for (std::vector<std::string>::const_iterator it = apis.begin();
 871            it != apis.end();
 872            ++it) {
 873         const std::string& api_name = *it;
 874         Feature* feature = api_feature_provider->GetFeature(api_name);
 875         DCHECK(feature);
 876
 877         // Internal APIs are included via require(api_name) from internal code
 878         // rather than chrome[api_name].
 879         if (feature->IsInternal())
 880           continue;
 881
 882         // If this API has a parent feature (and isn't marked 'noparent'),
 883         // then this must be a function or event, so we should not register.
 884         if (api_feature_provider->GetParent(feature) != NULL)
 885           continue;
 886
 887         if (context->IsAnyFeatureAvailableToContext(*feature))
 888           RegisterBinding(api_name, context);
 889       }
 890       if (CommandLine::ForCurrentProcess()->HasSwitch(::switches::kTestType)) {
 891         RegisterBinding("test", context);
 892       }
 893       break;
 894     }
 895   }
 896 }
 897
 898 void Dispatcher::RegisterBinding(const std::string& api_name,
 899                                  ScriptContext* context) {
 900   std::string bind_name;
 901   v8::Handle<v8::Object> bind_object =
 902       GetOrCreateBindObjectIfAvailable(api_name, &bind_name, context);
 903
 904   // Empty if the bind object failed to be created, probably because the
 905   // extension overrode chrome with a non-object, e.g. window.chrome = true.
 906   if (bind_object.IsEmpty())
 907     return;
 908
 909   v8::Local<v8::String> v8_api_name =
 910       v8::String::NewFromUtf8(context->isolate(), api_name.c_str());
 911   if (bind_object->HasRealNamedProperty(v8_api_name)) {
 912     // The bind object may already have the property if the API has been
 913     // registered before (or if the extension has put something there already,
 914     // but, whatevs).
 915     //
 916     // In the former case, we need to re-register the bindings for the APIs
 917     // which the extension now has permissions for (if any), but not touch any
 918     // others so that we don't destroy state such as event listeners.
 919     //
 920     // TODO(kalman): Only register available APIs to make this all moot.
 921     if (bind_object->HasRealNamedCallbackProperty(v8_api_name))
 922       return;  // lazy binding still there, nothing to do
 923     if (bind_object->Get(v8_api_name)->IsObject())
 924       return;  // binding has already been fully installed
 925   }
 926
 927   ModuleSystem* module_system = context->module_system();
 928   if (!source_map_.Contains(api_name)) {
 929     module_system->RegisterNativeHandler(
 930         api_name,
 931         scoped_ptr<NativeHandler>(new BindingGeneratingNativeHandler(
 932             module_system, api_name, "binding")));
 933     module_system->SetNativeLazyField(
 934         bind_object, bind_name, api_name, "binding");
 935   } else {
 936     module_system->SetLazyField(bind_object, bind_name, api_name, "binding");
 937   }
 938 }
 939
 940 // NOTE: please use the naming convention "foo_natives" for these.
 941 void Dispatcher::RegisterNativeHandlers(ModuleSystem* module_system,
 942                                         ScriptContext* context) {
 943   module_system->RegisterNativeHandler(
 944       "chrome", scoped_ptr<NativeHandler>(new ChromeNativeHandler(context)));
 945   module_system->RegisterNativeHandler(
 946       "lazy_background_page",
 947       scoped_ptr<NativeHandler>(new LazyBackgroundPageNativeHandler(context)));
 948   module_system->RegisterNativeHandler(
 949       "logging", scoped_ptr<NativeHandler>(new LoggingNativeHandler(context)));
 950   module_system->RegisterNativeHandler("schema_registry",
 951                                        v8_schema_registry_->AsNativeHandler());
 952   module_system->RegisterNativeHandler(
 953       "print", scoped_ptr<NativeHandler>(new PrintNativeHandler(context)));
 954   module_system->RegisterNativeHandler(
 955       "test_features",
 956       scoped_ptr<NativeHandler>(new TestFeaturesNativeHandler(context)));
 957   module_system->RegisterNativeHandler(
 958       "user_gestures",
 959       scoped_ptr<NativeHandler>(new UserGesturesNativeHandler(context)));
 960   module_system->RegisterNativeHandler(
 961       "utils", scoped_ptr<NativeHandler>(new UtilsNativeHandler(context)));
 962   module_system->RegisterNativeHandler(
 963       "v8_context",
 964       scoped_ptr<NativeHandler>(new V8ContextNativeHandler(context, this)));
 965
 966   const Extension* extension = context->extension();
 967   int manifest_version = extension ? extension->manifest_version() : 1;
 968   bool send_request_disabled =
 969       (extension && Manifest::IsUnpackedLocation(extension->location()) &&
 970        BackgroundInfo::HasLazyBackgroundPage(extension));
 971   module_system->RegisterNativeHandler(
 972       "process",
 973       scoped_ptr<NativeHandler>(new ProcessInfoNativeHandler(
 974           context,
 975           context->GetExtensionID(),
 976           context->GetContextTypeDescription(),
 977           ExtensionsRendererClient::Get()->IsIncognitoProcess(),
 978           manifest_version,
 979           send_request_disabled)));
 980
 981   module_system->RegisterNativeHandler(
 982       "event_natives",
 983       scoped_ptr<NativeHandler>(new EventBindings(this, context)));
 984   module_system->RegisterNativeHandler(
 985       "messaging_natives",
 986       scoped_ptr<NativeHandler>(MessagingBindings::Get(this, context)));
 987   module_system->RegisterNativeHandler(
 988       "apiDefinitions",
 989       scoped_ptr<NativeHandler>(new ApiDefinitionsNatives(this, context)));
 990   module_system->RegisterNativeHandler(
 991       "sendRequest",
 992       scoped_ptr<NativeHandler>(
 993           new SendRequestNatives(request_sender_.get(), context)));
 994   module_system->RegisterNativeHandler(
 995       "setIcon",
 996       scoped_ptr<NativeHandler>(
 997           new SetIconNatives(request_sender_.get(), context)));
 998   module_system->RegisterNativeHandler(
 999       "activityLogger",
1000       scoped_ptr<NativeHandler>(new APIActivityLogger(context)));
1001   module_system->RegisterNativeHandler(
1002       "renderViewObserverNatives",
1003       scoped_ptr<NativeHandler>(new RenderViewObserverNatives(context)));
1004
1005   // Natives used by multiple APIs.
1006   module_system->RegisterNativeHandler(
1007       "file_system_natives",
1008       scoped_ptr<NativeHandler>(new FileSystemNatives(context)));
1009
1010   // Custom bindings.
1011   module_system->RegisterNativeHandler(
1012       "app_runtime",
1013       scoped_ptr<NativeHandler>(new AppRuntimeCustomBindings(context)));
1014   module_system->RegisterNativeHandler(
1015       "blob_natives",
1016       scoped_ptr<NativeHandler>(new BlobNativeHandler(context)));
1017   module_system->RegisterNativeHandler(
1018       "context_menus",
1019       scoped_ptr<NativeHandler>(new ContextMenusCustomBindings(context)));
1020   module_system->RegisterNativeHandler(
1021       "css_natives", scoped_ptr<NativeHandler>(new CssNativeHandler(context)));
1022   module_system->RegisterNativeHandler(
1023       "document_natives",
1024       scoped_ptr<NativeHandler>(new DocumentCustomBindings(context)));
1025   module_system->RegisterNativeHandler(
1026       "i18n", scoped_ptr<NativeHandler>(new I18NCustomBindings(context)));
1027   module_system->RegisterNativeHandler(
1028       "id_generator",
1029       scoped_ptr<NativeHandler>(new IdGeneratorCustomBindings(context)));
1030   module_system->RegisterNativeHandler(
1031       "runtime", scoped_ptr<NativeHandler>(new RuntimeCustomBindings(context)));
1032
1033   delegate_->RegisterNativeHandlers(this, module_system, context);
1034 }
1035
1036 void Dispatcher::PopulateSourceMap() {
1037   // Libraries.
1038   source_map_.RegisterSource("entryIdManager", IDR_ENTRY_ID_MANAGER);
1039   source_map_.RegisterSource(kEventBindings, IDR_EVENT_BINDINGS_JS);
1040   source_map_.RegisterSource("imageUtil", IDR_IMAGE_UTIL_JS);
1041   source_map_.RegisterSource("json_schema", IDR_JSON_SCHEMA_JS);
1042   source_map_.RegisterSource("lastError", IDR_LAST_ERROR_JS);
1043   source_map_.RegisterSource("messaging", IDR_MESSAGING_JS);
1044   source_map_.RegisterSource("messaging_utils", IDR_MESSAGING_UTILS_JS);
1045   source_map_.RegisterSource(kSchemaUtils, IDR_SCHEMA_UTILS_JS);
1046   source_map_.RegisterSource("sendRequest", IDR_SEND_REQUEST_JS);
1047   source_map_.RegisterSource("setIcon", IDR_SET_ICON_JS);
1048   source_map_.RegisterSource("test", IDR_TEST_CUSTOM_BINDINGS_JS);
1049   source_map_.RegisterSource("unload_event", IDR_UNLOAD_EVENT_JS);
1050   source_map_.RegisterSource("utils", IDR_UTILS_JS);
1051
1052   // Custom bindings.
1053   source_map_.RegisterSource("app.runtime", IDR_APP_RUNTIME_CUSTOM_BINDINGS_JS);
1054   source_map_.RegisterSource("contextMenus",
1055                              IDR_CONTEXT_MENUS_CUSTOM_BINDINGS_JS);
1056   source_map_.RegisterSource("extension", IDR_EXTENSION_CUSTOM_BINDINGS_JS);
1057   source_map_.RegisterSource("i18n", IDR_I18N_CUSTOM_BINDINGS_JS);
1058   source_map_.RegisterSource("permissions", IDR_PERMISSIONS_CUSTOM_BINDINGS_JS);
1059   source_map_.RegisterSource("runtime", IDR_RUNTIME_CUSTOM_BINDINGS_JS);
1060   source_map_.RegisterSource("binding", IDR_BINDING_JS);
1061
1062   // Custom types sources.
1063   source_map_.RegisterSource("StorageArea", IDR_STORAGE_AREA_JS);
1064
1065   // Platform app sources that are not API-specific..
1066   source_map_.RegisterSource("platformApp", IDR_PLATFORM_APP_JS);
1067
1068   delegate_->PopulateSourceMap(&source_map_);
1069 }
1070
1071 bool Dispatcher::IsWithinPlatformApp() {
1072   for (std::set<std::string>::iterator iter = active_extension_ids_.begin();
1073        iter != active_extension_ids_.end();
1074        ++iter) {
1075     const Extension* extension = extensions_.GetByID(*iter);
1076     if (extension && extension->is_platform_app())
1077       return true;
1078   }
1079   return false;
1080 }
1081
1082 // TODO(kalman): This is checking for the wrong thing, it should be checking if
1083 // the frame's security origin is unique. The extension sandbox directive is
1084 // checked for in extensions/common/manifest_handlers/csp_info.cc.
1085 bool Dispatcher::IsSandboxedPage(const GURL& url) const {
1086   if (url.SchemeIs(kExtensionScheme)) {
1087     const Extension* extension = extensions_.GetByID(url.host());
1088     if (extension) {
1089       return SandboxedPageInfo::IsSandboxedPage(extension, url.path());
1090     }
1091   }
1092   return false;
1093 }
1094
1095 Feature::Context Dispatcher::ClassifyJavaScriptContext(
1096     const Extension* extension,
1097     int extension_group,
1098     const GURL& url,
1099     const blink::WebSecurityOrigin& origin) {
1100   DCHECK_GE(extension_group, 0);
1101   if (extension_group == EXTENSION_GROUP_CONTENT_SCRIPTS) {
1102     return extension ?  // TODO(kalman): when does this happen?
1103                Feature::CONTENT_SCRIPT_CONTEXT
1104                      : Feature::UNSPECIFIED_CONTEXT;
1105   }
1106
1107   // We have an explicit check for sandboxed pages before checking whether the
1108   // extension is active in this process because:
1109   // 1. Sandboxed pages run in the same process as regular extension pages, so
1110   //    the extension is considered active.
1111   // 2. ScriptContext creation (which triggers bindings injection) happens
1112   //    before the SecurityContext is updated with the sandbox flags (after
1113   //    reading the CSP header), so the caller can't check if the context's
1114   //    security origin is unique yet.
1115   if (IsSandboxedPage(url))
1116     return Feature::WEB_PAGE_CONTEXT;
1117
1118   if (extension && IsExtensionActive(extension->id())) {
1119     // |extension| is active in this process, but it could be either a true
1120     // extension process or within the extent of a hosted app. In the latter
1121     // case this would usually be considered a (blessed) web page context,
1122     // unless the extension in question is a component extension, in which case
1123     // we cheat and call it blessed.
1124     return (extension->is_hosted_app() &&
1125             extension->location() != Manifest::COMPONENT)
1126                ? Feature::BLESSED_WEB_PAGE_CONTEXT
1127                : Feature::BLESSED_EXTENSION_CONTEXT;
1128   }
1129
1130   // TODO(kalman): This isUnique() check is wrong, it should be performed as
1131   // part of IsSandboxedPage().
1132   if (!origin.isUnique() && extensions_.ExtensionBindingsAllowed(url)) {
1133     if (!extension)  // TODO(kalman): when does this happen?
1134       return Feature::UNSPECIFIED_CONTEXT;
1135     return extension->is_hosted_app() ? Feature::BLESSED_WEB_PAGE_CONTEXT
1136                                       : Feature::UNBLESSED_EXTENSION_CONTEXT;
1137   }
1138
1139   if (url.is_valid())
1140     return Feature::WEB_PAGE_CONTEXT;
1141
1142   return Feature::UNSPECIFIED_CONTEXT;
1143 }
1144
1145 v8::Handle<v8::Object> Dispatcher::GetOrCreateObject(
1146     const v8::Handle<v8::Object>& object,
1147     const std::string& field,
1148     v8::Isolate* isolate) {
1149   v8::Handle<v8::String> key = v8::String::NewFromUtf8(isolate, field.c_str());
1150   // If the object has a callback property, it is assumed it is an unavailable
1151   // API, so it is safe to delete. This is checked before GetOrCreateObject is
1152   // called.
1153   if (object->HasRealNamedCallbackProperty(key)) {
1154     object->Delete(key);
1155   } else if (object->HasRealNamedProperty(key)) {
1156     v8::Handle<v8::Value> value = object->Get(key);
1157     CHECK(value->IsObject());
1158     return v8::Handle<v8::Object>::Cast(value);
1159   }
1160
1161   v8::Handle<v8::Object> new_object = v8::Object::New(isolate);
1162   object->Set(key, new_object);
1163   return new_object;
1164 }
1165
1166 v8::Handle<v8::Object> Dispatcher::GetOrCreateBindObjectIfAvailable(
1167     const std::string& api_name,
1168     std::string* bind_name,
1169     ScriptContext* context) {
1170   std::vector<std::string> split;
1171   base::SplitString(api_name, '.', &split);
1172
1173   v8::Handle<v8::Object> bind_object;
1174
1175   // Check if this API has an ancestor. If the API's ancestor is available and
1176   // the API is not available, don't install the bindings for this API. If
1177   // the API is available and its ancestor is not, delete the ancestor and
1178   // install the bindings for the API. This is to prevent loading the ancestor
1179   // API schema if it will not be needed.
1180   //
1181   // For example:
1182   //  If app is available and app.window is not, just install app.
1183   //  If app.window is available and app is not, delete app and install
1184   //  app.window on a new object so app does not have to be loaded.
1185   FeatureProvider* api_feature_provider = FeatureProvider::GetAPIFeatures();
1186   std::string ancestor_name;
1187   bool only_ancestor_available = false;
1188
1189   for (size_t i = 0; i < split.size() - 1; ++i) {
1190     ancestor_name += (i ? "." : "") + split[i];
1191     if (api_feature_provider->GetFeature(ancestor_name) &&
1192         context->GetAvailability(ancestor_name).is_available() &&
1193         !context->GetAvailability(api_name).is_available()) {
1194       only_ancestor_available = true;
1195       break;
1196     }
1197
1198     if (bind_object.IsEmpty()) {
1199       bind_object = AsObjectOrEmpty(GetOrCreateChrome(context));
1200       if (bind_object.IsEmpty())
1201         return v8::Handle<v8::Object>();
1202     }
1203     bind_object = GetOrCreateObject(bind_object, split[i], context->isolate());
1204   }
1205
1206   if (only_ancestor_available)
1207     return v8::Handle<v8::Object>();
1208
1209   if (bind_name)
1210     *bind_name = split.back();
1211
1212   return bind_object.IsEmpty() ? AsObjectOrEmpty(GetOrCreateChrome(context))
1213                                : bind_object;
1214 }
1215
1216 }  // namespace extensions