GPU workaround to simulate Out of Memory errors with large textures
[chromium-blink-merge.git] / content / common / page_state_serialization.cc
blob4d9ea3b0890edca01b65064d9418aaa6c4609e30
1 // Copyright 2013 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.
5 #include "content/common/page_state_serialization.h"
7 #include <algorithm>
8 #include <limits>
10 #include "base/pickle.h"
11 #include "base/strings/string_number_conversions.h"
12 #include "base/strings/string_util.h"
13 #include "base/strings/utf_string_conversions.h"
14 #include "ui/gfx/screen.h"
16 namespace content {
17 namespace {
19 #if defined(OS_ANDROID)
20 float g_device_scale_factor_for_testing = 0.0;
21 #endif
23 //-----------------------------------------------------------------------------
25 void AppendDataToHttpBody(ExplodedHttpBody* http_body, const char* data,
26 int data_length) {
27 ExplodedHttpBodyElement element;
28 element.type = blink::WebHTTPBody::Element::TypeData;
29 element.data.assign(data, data_length);
30 http_body->elements.push_back(element);
33 void AppendFileRangeToHttpBody(ExplodedHttpBody* http_body,
34 const base::NullableString16& file_path,
35 int file_start,
36 int file_length,
37 double file_modification_time) {
38 ExplodedHttpBodyElement element;
39 element.type = blink::WebHTTPBody::Element::TypeFile;
40 element.file_path = file_path;
41 element.file_start = file_start;
42 element.file_length = file_length;
43 element.file_modification_time = file_modification_time;
44 http_body->elements.push_back(element);
47 void AppendURLRangeToHttpBody(ExplodedHttpBody* http_body,
48 const GURL& url,
49 int file_start,
50 int file_length,
51 double file_modification_time) {
52 ExplodedHttpBodyElement element;
53 element.type = blink::WebHTTPBody::Element::TypeFileSystemURL;
54 element.filesystem_url = url;
55 element.file_start = file_start;
56 element.file_length = file_length;
57 element.file_modification_time = file_modification_time;
58 http_body->elements.push_back(element);
61 void AppendBlobToHttpBody(ExplodedHttpBody* http_body,
62 const std::string& uuid) {
63 ExplodedHttpBodyElement element;
64 element.type = blink::WebHTTPBody::Element::TypeBlob;
65 element.blob_uuid = uuid;
66 http_body->elements.push_back(element);
69 //----------------------------------------------------------------------------
71 void AppendReferencedFilesFromHttpBody(
72 const std::vector<ExplodedHttpBodyElement>& elements,
73 std::vector<base::NullableString16>* referenced_files) {
74 for (size_t i = 0; i < elements.size(); ++i) {
75 if (elements[i].type == blink::WebHTTPBody::Element::TypeFile)
76 referenced_files->push_back(elements[i].file_path);
80 bool AppendReferencedFilesFromDocumentState(
81 const std::vector<base::NullableString16>& document_state,
82 std::vector<base::NullableString16>* referenced_files) {
83 if (document_state.empty())
84 return true;
86 // This algorithm is adapted from Blink's core/html/FormController.cpp code.
87 // We only care about how that code worked when this code snapshot was taken
88 // as this code is only needed for backwards compat.
90 // For reference, see FormController::formStatesFromStateVector at:
91 // http://src.chromium.org/viewvc/blink/trunk/Source/core/html/FormController.cpp?pathrev=152274
93 size_t index = 0;
95 if (document_state.size() < 3)
96 return false;
98 index++; // Skip over magic signature.
99 index++; // Skip over form key.
101 size_t item_count;
102 if (!base::StringToSizeT(document_state[index++].string(), &item_count))
103 return false;
105 while (item_count--) {
106 if (index + 1 >= document_state.size())
107 return false;
109 index++; // Skip over name.
110 const base::NullableString16& type = document_state[index++];
112 if (index >= document_state.size())
113 return false;
115 size_t value_size;
116 if (!base::StringToSizeT(document_state[index++].string(), &value_size))
117 return false;
119 if (index + value_size > document_state.size() ||
120 index + value_size < index) // Check for overflow.
121 return false;
123 if (EqualsASCII(type.string(), "file")) {
124 if (value_size != 2)
125 return false;
127 referenced_files->push_back(document_state[index++]);
128 index++; // Skip over display name.
129 } else {
130 index += value_size;
134 return true;
137 bool RecursivelyAppendReferencedFiles(
138 const ExplodedFrameState& frame_state,
139 std::vector<base::NullableString16>* referenced_files) {
140 if (!frame_state.http_body.is_null) {
141 AppendReferencedFilesFromHttpBody(frame_state.http_body.elements,
142 referenced_files);
145 if (!AppendReferencedFilesFromDocumentState(frame_state.document_state,
146 referenced_files))
147 return false;
149 for (size_t i = 0; i < frame_state.children.size(); ++i) {
150 if (!RecursivelyAppendReferencedFiles(frame_state.children[i],
151 referenced_files))
152 return false;
155 return true;
158 //----------------------------------------------------------------------------
160 struct SerializeObject {
161 SerializeObject()
162 : version(0),
163 parse_error(false) {
166 SerializeObject(const char* data, int len)
167 : pickle(data, len),
168 version(0),
169 parse_error(false) {
170 iter = PickleIterator(pickle);
173 std::string GetAsString() {
174 return std::string(static_cast<const char*>(pickle.data()), pickle.size());
177 Pickle pickle;
178 PickleIterator iter;
179 int version;
180 bool parse_error;
183 // Version ID of serialized format.
184 // 11: Min version
185 // 12: Adds support for contains_passwords in HTTP body
186 // 13: Adds support for URL (FileSystem URL)
187 // 14: Adds list of referenced files, version written only for first item.
188 // 15: Removes a bunch of values we defined but never used.
189 // 16: Switched from blob urls to blob uuids.
190 // 17: Add a target frame id number.
191 // 18: Add referrer policy.
192 // 19: Remove target frame id, which was a bad idea, and original url string,
193 // which is no longer used.
194 // 20: Add pinch viewport scroll offset, the offset of the pinched zoomed
195 // viewport within the unzoomed main frame.
196 // 21: Add frame sequence number
198 // NOTE: If the version is -1, then the pickle contains only a URL string.
199 // See ReadPageState.
201 const int kMinVersion = 11;
202 const int kCurrentVersion = 21;
204 // A bunch of convenience functions to read/write to SerializeObjects. The
205 // de-serializers assume the input data will be in the correct format and fall
206 // back to returning safe defaults when not.
208 void WriteData(const void* data, int length, SerializeObject* obj) {
209 obj->pickle.WriteData(static_cast<const char*>(data), length);
212 void ReadData(SerializeObject* obj, const void** data, int* length) {
213 const char* tmp;
214 if (obj->iter.ReadData(&tmp, length)) {
215 *data = tmp;
216 } else {
217 obj->parse_error = true;
218 *data = NULL;
219 *length = 0;
223 void WriteInteger(int data, SerializeObject* obj) {
224 obj->pickle.WriteInt(data);
227 int ReadInteger(SerializeObject* obj) {
228 int tmp;
229 if (obj->iter.ReadInt(&tmp))
230 return tmp;
231 obj->parse_error = true;
232 return 0;
235 void WriteInteger64(int64 data, SerializeObject* obj) {
236 obj->pickle.WriteInt64(data);
239 int64 ReadInteger64(SerializeObject* obj) {
240 int64 tmp = 0;
241 if (obj->iter.ReadInt64(&tmp))
242 return tmp;
243 obj->parse_error = true;
244 return 0;
247 void WriteReal(double data, SerializeObject* obj) {
248 WriteData(&data, sizeof(double), obj);
251 double ReadReal(SerializeObject* obj) {
252 const void* tmp = NULL;
253 int length = 0;
254 double value = 0.0;
255 ReadData(obj, &tmp, &length);
256 if (length == static_cast<int>(sizeof(double))) {
257 // Use memcpy, as tmp may not be correctly aligned.
258 memcpy(&value, tmp, sizeof(double));
259 } else {
260 obj->parse_error = true;
262 return value;
265 void WriteBoolean(bool data, SerializeObject* obj) {
266 obj->pickle.WriteInt(data ? 1 : 0);
269 bool ReadBoolean(SerializeObject* obj) {
270 bool tmp;
271 if (obj->iter.ReadBool(&tmp))
272 return tmp;
273 obj->parse_error = true;
274 return false;
277 void WriteGURL(const GURL& url, SerializeObject* obj) {
278 obj->pickle.WriteString(url.possibly_invalid_spec());
281 GURL ReadGURL(SerializeObject* obj) {
282 std::string spec;
283 if (obj->iter.ReadString(&spec))
284 return GURL(spec);
285 obj->parse_error = true;
286 return GURL();
289 void WriteStdString(const std::string& s, SerializeObject* obj) {
290 obj->pickle.WriteString(s);
293 std::string ReadStdString(SerializeObject* obj) {
294 std::string s;
295 if (obj->iter.ReadString(&s))
296 return s;
297 obj->parse_error = true;
298 return std::string();
301 // WriteString pickles the NullableString16 as <int length><char16* data>.
302 // If length == -1, then the NullableString16 itself is null. Otherwise the
303 // length is the number of char16 (not bytes) in the NullableString16.
304 void WriteString(const base::NullableString16& str, SerializeObject* obj) {
305 if (str.is_null()) {
306 obj->pickle.WriteInt(-1);
307 } else {
308 const base::char16* data = str.string().data();
309 size_t length_in_bytes = str.string().length() * sizeof(base::char16);
311 CHECK_LT(length_in_bytes,
312 static_cast<size_t>(std::numeric_limits<int>::max()));
313 obj->pickle.WriteInt(length_in_bytes);
314 obj->pickle.WriteBytes(data, length_in_bytes);
318 // This reads a serialized NullableString16 from obj. If a string can't be
319 // read, NULL is returned.
320 const base::char16* ReadStringNoCopy(SerializeObject* obj, int* num_chars) {
321 int length_in_bytes;
322 if (!obj->iter.ReadInt(&length_in_bytes)) {
323 obj->parse_error = true;
324 return NULL;
327 if (length_in_bytes < 0)
328 return NULL;
330 const char* data;
331 if (!obj->iter.ReadBytes(&data, length_in_bytes)) {
332 obj->parse_error = true;
333 return NULL;
336 if (num_chars)
337 *num_chars = length_in_bytes / sizeof(base::char16);
338 return reinterpret_cast<const base::char16*>(data);
341 base::NullableString16 ReadString(SerializeObject* obj) {
342 int num_chars;
343 const base::char16* chars = ReadStringNoCopy(obj, &num_chars);
344 return chars ?
345 base::NullableString16(base::string16(chars, num_chars), false) :
346 base::NullableString16();
349 template <typename T>
350 void WriteAndValidateVectorSize(const std::vector<T>& v, SerializeObject* obj) {
351 CHECK_LT(v.size(), std::numeric_limits<int>::max() / sizeof(T));
352 WriteInteger(static_cast<int>(v.size()), obj);
355 size_t ReadAndValidateVectorSize(SerializeObject* obj, size_t element_size) {
356 size_t num_elements = static_cast<size_t>(ReadInteger(obj));
358 // Ensure that resizing a vector to size num_elements makes sense.
359 if (std::numeric_limits<int>::max() / element_size <= num_elements) {
360 obj->parse_error = true;
361 return 0;
364 // Ensure that it is plausible for the pickle to contain num_elements worth
365 // of data.
366 if (obj->pickle.payload_size() <= num_elements) {
367 obj->parse_error = true;
368 return 0;
371 return num_elements;
374 // Writes a Vector of strings into a SerializeObject for serialization.
375 void WriteStringVector(
376 const std::vector<base::NullableString16>& data, SerializeObject* obj) {
377 WriteAndValidateVectorSize(data, obj);
378 for (size_t i = 0; i < data.size(); ++i) {
379 WriteString(data[i], obj);
383 void ReadStringVector(SerializeObject* obj,
384 std::vector<base::NullableString16>* result) {
385 size_t num_elements =
386 ReadAndValidateVectorSize(obj, sizeof(base::NullableString16));
388 result->resize(num_elements);
389 for (size_t i = 0; i < num_elements; ++i)
390 (*result)[i] = ReadString(obj);
393 // Writes an ExplodedHttpBody object into a SerializeObject for serialization.
394 void WriteHttpBody(const ExplodedHttpBody& http_body, SerializeObject* obj) {
395 WriteBoolean(!http_body.is_null, obj);
397 if (http_body.is_null)
398 return;
400 WriteAndValidateVectorSize(http_body.elements, obj);
401 for (size_t i = 0; i < http_body.elements.size(); ++i) {
402 const ExplodedHttpBodyElement& element = http_body.elements[i];
403 WriteInteger(element.type, obj);
404 if (element.type == blink::WebHTTPBody::Element::TypeData) {
405 WriteData(element.data.data(), static_cast<int>(element.data.size()),
406 obj);
407 } else if (element.type == blink::WebHTTPBody::Element::TypeFile) {
408 WriteString(element.file_path, obj);
409 WriteInteger64(element.file_start, obj);
410 WriteInteger64(element.file_length, obj);
411 WriteReal(element.file_modification_time, obj);
412 } else if (element.type ==
413 blink::WebHTTPBody::Element::TypeFileSystemURL) {
414 WriteGURL(element.filesystem_url, obj);
415 WriteInteger64(element.file_start, obj);
416 WriteInteger64(element.file_length, obj);
417 WriteReal(element.file_modification_time, obj);
418 } else {
419 DCHECK(element.type == blink::WebHTTPBody::Element::TypeBlob);
420 WriteStdString(element.blob_uuid, obj);
423 WriteInteger64(http_body.identifier, obj);
424 WriteBoolean(http_body.contains_passwords, obj);
427 void ReadHttpBody(SerializeObject* obj, ExplodedHttpBody* http_body) {
428 // An initial boolean indicates if we have an HTTP body.
429 if (!ReadBoolean(obj))
430 return;
431 http_body->is_null = false;
433 int num_elements = ReadInteger(obj);
435 for (int i = 0; i < num_elements; ++i) {
436 int type = ReadInteger(obj);
437 if (type == blink::WebHTTPBody::Element::TypeData) {
438 const void* data;
439 int length = -1;
440 ReadData(obj, &data, &length);
441 if (length >= 0) {
442 AppendDataToHttpBody(http_body, static_cast<const char*>(data),
443 length);
445 } else if (type == blink::WebHTTPBody::Element::TypeFile) {
446 base::NullableString16 file_path = ReadString(obj);
447 int64 file_start = ReadInteger64(obj);
448 int64 file_length = ReadInteger64(obj);
449 double file_modification_time = ReadReal(obj);
450 AppendFileRangeToHttpBody(http_body, file_path, file_start, file_length,
451 file_modification_time);
452 } else if (type == blink::WebHTTPBody::Element::TypeFileSystemURL) {
453 GURL url = ReadGURL(obj);
454 int64 file_start = ReadInteger64(obj);
455 int64 file_length = ReadInteger64(obj);
456 double file_modification_time = ReadReal(obj);
457 AppendURLRangeToHttpBody(http_body, url, file_start, file_length,
458 file_modification_time);
459 } else if (type == blink::WebHTTPBody::Element::TypeBlob) {
460 if (obj->version >= 16) {
461 std::string blob_uuid = ReadStdString(obj);
462 AppendBlobToHttpBody(http_body, blob_uuid);
463 } else {
464 ReadGURL(obj); // Skip the obsolete blob url value.
468 http_body->identifier = ReadInteger64(obj);
470 if (obj->version >= 12)
471 http_body->contains_passwords = ReadBoolean(obj);
474 // Writes the ExplodedFrameState data into the SerializeObject object for
475 // serialization.
476 void WriteFrameState(
477 const ExplodedFrameState& state, SerializeObject* obj, bool is_top) {
478 // WARNING: This data may be persisted for later use. As such, care must be
479 // taken when changing the serialized format. If a new field needs to be
480 // written, only adding at the end will make it easier to deal with loading
481 // older versions. Similarly, this should NOT save fields with sensitive
482 // data, such as password fields.
484 WriteString(state.url_string, obj);
485 WriteString(state.target, obj);
486 WriteInteger(state.scroll_offset.x(), obj);
487 WriteInteger(state.scroll_offset.y(), obj);
488 WriteString(state.referrer, obj);
490 WriteStringVector(state.document_state, obj);
492 WriteReal(state.page_scale_factor, obj);
493 WriteInteger64(state.item_sequence_number, obj);
494 WriteInteger64(state.document_sequence_number, obj);
495 WriteInteger64(state.frame_sequence_number, obj);
496 WriteInteger(state.referrer_policy, obj);
497 WriteReal(state.pinch_viewport_scroll_offset.x(), obj);
498 WriteReal(state.pinch_viewport_scroll_offset.y(), obj);
500 bool has_state_object = !state.state_object.is_null();
501 WriteBoolean(has_state_object, obj);
502 if (has_state_object)
503 WriteString(state.state_object, obj);
505 WriteHttpBody(state.http_body, obj);
507 // NOTE: It is a quirk of the format that we still have to write the
508 // http_content_type field when the HTTP body is null. That's why this code
509 // is here instead of inside WriteHttpBody.
510 WriteString(state.http_body.http_content_type, obj);
512 // Subitems
513 const std::vector<ExplodedFrameState>& children = state.children;
514 WriteAndValidateVectorSize(children, obj);
515 for (size_t i = 0; i < children.size(); ++i)
516 WriteFrameState(children[i], obj, false);
519 void ReadFrameState(SerializeObject* obj, bool is_top,
520 ExplodedFrameState* state) {
521 if (obj->version < 14 && !is_top)
522 ReadInteger(obj); // Skip over redundant version field.
524 state->url_string = ReadString(obj);
526 if (obj->version < 19)
527 ReadString(obj); // Skip obsolete original url string field.
529 state->target = ReadString(obj);
530 if (obj->version < 15) {
531 ReadString(obj); // Skip obsolete parent field.
532 ReadString(obj); // Skip obsolete title field.
533 ReadString(obj); // Skip obsolete alternate title field.
534 ReadReal(obj); // Skip obsolete visited time field.
537 int x = ReadInteger(obj);
538 int y = ReadInteger(obj);
539 state->scroll_offset = gfx::Point(x, y);
541 if (obj->version < 15) {
542 ReadBoolean(obj); // Skip obsolete target item flag.
543 ReadInteger(obj); // Skip obsolete visit count field.
545 state->referrer = ReadString(obj);
547 ReadStringVector(obj, &state->document_state);
549 state->page_scale_factor = ReadReal(obj);
550 state->item_sequence_number = ReadInteger64(obj);
551 state->document_sequence_number = ReadInteger64(obj);
552 if (obj->version >= 21)
553 state->frame_sequence_number = ReadInteger64(obj);
555 if (obj->version >= 17 && obj->version < 19)
556 ReadInteger64(obj); // Skip obsolete target frame id number.
558 if (obj->version >= 18) {
559 state->referrer_policy =
560 static_cast<blink::WebReferrerPolicy>(ReadInteger(obj));
563 if (obj->version >= 20) {
564 double x = ReadReal(obj);
565 double y = ReadReal(obj);
566 state->pinch_viewport_scroll_offset = gfx::PointF(x, y);
567 } else {
568 state->pinch_viewport_scroll_offset = gfx::PointF(-1, -1);
571 bool has_state_object = ReadBoolean(obj);
572 if (has_state_object)
573 state->state_object = ReadString(obj);
575 ReadHttpBody(obj, &state->http_body);
577 // NOTE: It is a quirk of the format that we still have to read the
578 // http_content_type field when the HTTP body is null. That's why this code
579 // is here instead of inside ReadHttpBody.
580 state->http_body.http_content_type = ReadString(obj);
582 if (obj->version < 14)
583 ReadString(obj); // Skip unused referrer string.
585 #if defined(OS_ANDROID)
586 if (obj->version == 11) {
587 // Now-unused values that shipped in this version of Chrome for Android when
588 // it was on a private branch.
589 ReadReal(obj);
590 ReadBoolean(obj);
592 // In this version, page_scale_factor included device_scale_factor and
593 // scroll offsets were premultiplied by pageScaleFactor.
594 if (state->page_scale_factor) {
595 float device_scale_factor = g_device_scale_factor_for_testing;
596 if (!device_scale_factor) {
597 device_scale_factor =
598 gfx::Screen::GetNativeScreen()->GetPrimaryDisplay().
599 device_scale_factor();
601 state->scroll_offset =
602 gfx::Point(state->scroll_offset.x() / state->page_scale_factor,
603 state->scroll_offset.y() / state->page_scale_factor);
604 state->page_scale_factor /= device_scale_factor;
607 #endif
609 // Subitems
610 size_t num_children =
611 ReadAndValidateVectorSize(obj, sizeof(ExplodedFrameState));
612 state->children.resize(num_children);
613 for (size_t i = 0; i < num_children; ++i)
614 ReadFrameState(obj, false, &state->children[i]);
617 void WritePageState(const ExplodedPageState& state, SerializeObject* obj) {
618 WriteInteger(obj->version, obj);
619 WriteStringVector(state.referenced_files, obj);
620 WriteFrameState(state.top, obj, true);
623 void ReadPageState(SerializeObject* obj, ExplodedPageState* state) {
624 obj->version = ReadInteger(obj);
626 if (obj->version == -1) {
627 GURL url = ReadGURL(obj);
628 // NOTE: GURL::possibly_invalid_spec() always returns valid UTF-8.
629 state->top.url_string =
630 base::NullableString16(
631 base::UTF8ToUTF16(url.possibly_invalid_spec()), false);
632 return;
635 if (obj->version > kCurrentVersion || obj->version < kMinVersion) {
636 obj->parse_error = true;
637 return;
640 if (obj->version >= 14)
641 ReadStringVector(obj, &state->referenced_files);
643 ReadFrameState(obj, true, &state->top);
645 if (obj->version < 14)
646 RecursivelyAppendReferencedFiles(state->top, &state->referenced_files);
648 // De-dupe
649 state->referenced_files.erase(
650 std::unique(state->referenced_files.begin(),
651 state->referenced_files.end()),
652 state->referenced_files.end());
655 } // namespace
657 ExplodedHttpBodyElement::ExplodedHttpBodyElement()
658 : type(blink::WebHTTPBody::Element::TypeData),
659 file_start(0),
660 file_length(-1),
661 file_modification_time(std::numeric_limits<double>::quiet_NaN()) {
664 ExplodedHttpBodyElement::~ExplodedHttpBodyElement() {
667 ExplodedHttpBody::ExplodedHttpBody()
668 : identifier(0),
669 contains_passwords(false),
670 is_null(true) {
673 ExplodedHttpBody::~ExplodedHttpBody() {
676 ExplodedFrameState::ExplodedFrameState()
677 : item_sequence_number(0),
678 document_sequence_number(0),
679 frame_sequence_number(0),
680 page_scale_factor(0.0),
681 referrer_policy(blink::WebReferrerPolicyDefault) {
684 ExplodedFrameState::ExplodedFrameState(const ExplodedFrameState& other) {
685 assign(other);
688 ExplodedFrameState::~ExplodedFrameState() {
691 void ExplodedFrameState::operator=(const ExplodedFrameState& other) {
692 if (&other != this)
693 assign(other);
696 void ExplodedFrameState::assign(const ExplodedFrameState& other) {
697 url_string = other.url_string;
698 referrer = other.referrer;
699 target = other.target;
700 state_object = other.state_object;
701 document_state = other.document_state;
702 pinch_viewport_scroll_offset = other.pinch_viewport_scroll_offset;
703 scroll_offset = other.scroll_offset;
704 item_sequence_number = other.item_sequence_number;
705 document_sequence_number = other.document_sequence_number;
706 frame_sequence_number = other.frame_sequence_number;
707 page_scale_factor = other.page_scale_factor;
708 referrer_policy = other.referrer_policy;
709 http_body = other.http_body;
710 children = other.children;
713 ExplodedPageState::ExplodedPageState() {
716 ExplodedPageState::~ExplodedPageState() {
719 bool DecodePageState(const std::string& encoded, ExplodedPageState* exploded) {
720 *exploded = ExplodedPageState();
722 if (encoded.empty())
723 return true;
725 SerializeObject obj(encoded.data(), static_cast<int>(encoded.size()));
726 ReadPageState(&obj, exploded);
727 return !obj.parse_error;
730 bool EncodePageState(const ExplodedPageState& exploded, std::string* encoded) {
731 SerializeObject obj;
732 obj.version = kCurrentVersion;
733 WritePageState(exploded, &obj);
734 *encoded = obj.GetAsString();
735 return true;
738 #if defined(OS_ANDROID)
739 bool DecodePageStateWithDeviceScaleFactorForTesting(
740 const std::string& encoded,
741 float device_scale_factor,
742 ExplodedPageState* exploded) {
743 g_device_scale_factor_for_testing = device_scale_factor;
744 bool rv = DecodePageState(encoded, exploded);
745 g_device_scale_factor_for_testing = 0.0;
746 return rv;
748 #endif
750 } // namespace content