extensions/browser/extension_host.h

   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 #ifndef EXTENSIONS_BROWSER_EXTENSION_HOST_H_
   6 #define EXTENSIONS_BROWSER_EXTENSION_HOST_H_
   7
   8 #include <set>
   9 #include <string>
  10
  11 #include "base/logging.h"
  12 #include "base/memory/scoped_ptr.h"
  13 #include "base/observer_list.h"
  14 #include "base/timer/elapsed_timer.h"
  15 #include "content/public/browser/web_contents_delegate.h"
  16 #include "content/public/browser/web_contents_observer.h"
  17 #include "extensions/browser/deferred_start_render_host.h"
  18 #include "extensions/browser/extension_function_dispatcher.h"
  19 #include "extensions/browser/extension_registry_observer.h"
  20 #include "extensions/common/stack_frame.h"
  21 #include "extensions/common/view_type.h"
  22
  23 class PrefsTabHelper;
  24
  25 namespace content {
  26 class BrowserContext;
  27 class RenderProcessHost;
  28 class RenderWidgetHostView;
  29 class SiteInstance;
  30 }
  31
  32 namespace extensions {
  33 class Extension;
  34 class ExtensionHostDelegate;
  35 class ExtensionHostObserver;
  36 class ExtensionHostQueue;
  37 class WindowController;
  38
  39 // This class is the browser component of an extension component's RenderView.
  40 // It handles setting up the renderer process, if needed, with special
  41 // privileges available to extensions.  It may have a view to be shown in the
  42 // browser UI, or it may be hidden.
  43 //
  44 // If you are adding code that only affects visible extension views (and not
  45 // invisible background pages) you should add it to ExtensionViewHost.
  46 class ExtensionHost : public DeferredStartRenderHost,
  47                       public content::WebContentsDelegate,
  48                       public content::WebContentsObserver,
  49                       public ExtensionFunctionDispatcher::Delegate,
  50                       public ExtensionRegistryObserver {
  51  public:
  52   ExtensionHost(const Extension* extension,
  53                 content::SiteInstance* site_instance,
  54                 const GURL& url, ViewType host_type);
  55   ~ExtensionHost() override;
  56
  57   const Extension* extension() const { return extension_; }
  58   const std::string& extension_id() const { return extension_id_; }
  59   content::WebContents* host_contents() const { return host_contents_.get(); }
  60   content::RenderViewHost* render_view_host() const;
  61   content::RenderProcessHost* render_process_host() const;
  62   bool has_loaded_once() const { return has_loaded_once_; }
  63   const GURL& initial_url() const { return initial_url_; }
  64   bool document_element_available() const {
  65     return document_element_available_;
  66   }
  67
  68   content::BrowserContext* browser_context() { return browser_context_; }
  69
  70   ViewType extension_host_type() const { return extension_host_type_; }
  71   const GURL& GetURL() const;
  72
  73   // Returns true if the render view is initialized and didn't crash.
  74   bool IsRenderViewLive() const;
  75
  76   // Prepares to initializes our RenderViewHost by creating its RenderView and
  77   // navigating to this host's url. Uses host_view for the RenderViewHost's view
  78   // (can be NULL). This happens delayed to avoid locking the UI.
  79   void CreateRenderViewSoon();
  80
  81   // Closes this host (results in [possibly asynchronous] deletion).
  82   void Close();
  83
  84   // Typical observer interface.
  85   void AddObserver(ExtensionHostObserver* observer);
  86   void RemoveObserver(ExtensionHostObserver* observer);
  87
  88   // Called when an event is dispatched to the event page associated with this
  89   // ExtensionHost.
  90   void OnBackgroundEventDispatched(const std::string& event_name, int event_id);
  91
  92   // Called by the ProcessManager when a network request is started by the
  93   // extension corresponding to this ExtensionHost.
  94   void OnNetworkRequestStarted(uint64 request_id);
  95
  96   // Called by the ProcessManager when a previously started network request is
  97   // finished.
  98   void OnNetworkRequestDone(uint64 request_id);
  99
 100   // content::WebContentsObserver:
 101   bool OnMessageReceived(const IPC::Message& message,
 102                          content::RenderFrameHost* host) override;
 103   void RenderViewCreated(content::RenderViewHost* render_view_host) override;
 104   void RenderViewDeleted(content::RenderViewHost* render_view_host) override;
 105   void RenderViewReady() override;
 106   void RenderProcessGone(base::TerminationStatus status) override;
 107   void DocumentAvailableInMainFrame() override;
 108   void DidStartLoading() override;
 109   void DidStopLoading() override;
 110
 111   // content::WebContentsDelegate:
 112   content::JavaScriptDialogManager* GetJavaScriptDialogManager(
 113       content::WebContents* source) override;
 114   void AddNewContents(content::WebContents* source,
 115                       content::WebContents* new_contents,
 116                       WindowOpenDisposition disposition,
 117                       const gfx::Rect& initial_rect,
 118                       bool user_gesture,
 119                       bool* was_blocked) override;
 120   void CloseContents(content::WebContents* contents) override;
 121   void RequestMediaAccessPermission(
 122       content::WebContents* web_contents,
 123       const content::MediaStreamRequest& request,
 124       const content::MediaResponseCallback& callback) override;
 125   bool CheckMediaAccessPermission(content::WebContents* web_contents,
 126                                   const GURL& security_origin,
 127                                   content::MediaStreamType type) override;
 128   bool IsNeverVisible(content::WebContents* web_contents) override;
 129
 130   // ExtensionRegistryObserver:
 131   void OnExtensionUnloaded(content::BrowserContext* browser_context,
 132                            const Extension* extension,
 133                            UnloadedExtensionInfo::Reason reason) override;
 134
 135  protected:
 136   // Called each time this ExtensionHost completes a load finishes loading,
 137   // before any stop-loading notifications or observer methods are called.
 138   virtual void OnDidStopFirstLoad();
 139
 140   // Navigates to the initial page.
 141   virtual void LoadInitialURL();
 142
 143   // Returns true if we're hosting a background page.
 144   virtual bool IsBackgroundPage() const;
 145
 146  private:
 147   // DeferredStartRenderHost:
 148   void CreateRenderViewNow() override;
 149   void AddDeferredStartRenderHostObserver(
 150       DeferredStartRenderHostObserver* observer) override;
 151   void RemoveDeferredStartRenderHostObserver(
 152       DeferredStartRenderHostObserver* observer) override;
 153
 154   // Message handlers.
 155   void OnEventAck(int event_id);
 156   void OnIncrementLazyKeepaliveCount();
 157   void OnDecrementLazyKeepaliveCount();
 158
 159   // Records UMA for load events.
 160   void RecordStopLoadingUMA();
 161
 162   // Delegate for functionality that cannot exist in the extensions module.
 163   scoped_ptr<ExtensionHostDelegate> delegate_;
 164
 165   // The extension that we're hosting in this view.
 166   const Extension* extension_;
 167
 168   // Id of extension that we're hosting in this view.
 169   const std::string extension_id_;
 170
 171   // The browser context that this host is tied to.
 172   content::BrowserContext* browser_context_;
 173
 174   // The host for our HTML content.
 175   scoped_ptr<content::WebContents> host_contents_;
 176
 177   // A weak pointer to the current or pending RenderViewHost. We don't access
 178   // this through the host_contents because we want to deal with the pending
 179   // host, so we can send messages to it before it finishes loading.
 180   content::RenderViewHost* render_view_host_;
 181
 182   // Whether the ExtensionHost has finished loading some content at least once.
 183   // There may be subsequent loads - such as reloads and navigations - and this
 184   // will not affect its value (it will remain true).
 185   bool has_loaded_once_;
 186
 187   // True if the main frame has finished parsing.
 188   bool document_element_available_;
 189
 190   // The original URL of the page being hosted.
 191   GURL initial_url_;
 192
 193   // Messages sent out to the renderer that have not been acknowledged yet.
 194   std::set<int> unacked_messages_;
 195
 196   // The type of view being hosted.
 197   ViewType extension_host_type_;
 198
 199   // Measures how long since the ExtensionHost object was created. This can be
 200   // used to measure the responsiveness of UI. For example, it's important to
 201   // keep this as low as possible for popups. Contrast this to |load_start_|,
 202   // for which a low value does not necessarily mean a responsive UI, as
 203   // ExtensionHosts may sit in an ExtensionHostQueue for a long time.
 204   base::ElapsedTimer create_start_;
 205
 206   // Measures how long since the initial URL started loading. This timer is
 207   // started only once the ExtensionHost has exited the ExtensionHostQueue.
 208   scoped_ptr<base::ElapsedTimer> load_start_;
 209
 210   base::ObserverList<ExtensionHostObserver> observer_list_;
 211   base::ObserverList<DeferredStartRenderHostObserver>
 212       deferred_start_render_host_observer_list_;
 213
 214   DISALLOW_COPY_AND_ASSIGN(ExtensionHost);
 215 };
 216
 217 }  // namespace extensions
 218
 219 #endif  // EXTENSIONS_BROWSER_EXTENSION_HOST_H_