Create MediaValuesCached and TokenPreloadScanner on the parser thread

third_party/WebKit/Source/core/css/MediaValuesCached.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef MediaValuesCached_h
 #define MediaValuesCached_h
 
 #include "core/CoreExport.h"
 #include "core/css/MediaValues.h"
 
 namespace blink {
 
 class CORE_EXPORT MediaValuesCached final : public MediaValues {
 public:
-    struct MediaValuesCachedData {
+    struct MediaValuesCachedData final {
         DISALLOW_NEW();
         // Members variables must be thread safe, since they're copied to the parser thread
         double viewportWidth;
         double viewportHeight;
         int deviceWidth;
         int deviceHeight;
         float devicePixelRatio;
         int colorBitsPerComponent;
         int monochromeBitsPerComponent;
         PointerType primaryPointerType;
@@ skipping 17 matching lines @@
             , primaryPointerType(PointerTypeNone)
             , availablePointerTypes(PointerTypeNone)
             , primaryHoverType(HoverTypeNone)
             , availableHoverTypes(HoverTypeNone)
             , defaultFontSize(16)
             , threeDEnabled(false)
             , strictMode(true)
             , displayMode(WebDisplayModeBrowser)
         {
         }
+
+        explicit MediaValuesCachedData(Document&);
+
+        MediaValuesCachedData deepCopy() const
+        {
+            MediaValuesCachedData data;
+            data.viewportWidth = viewportWidth;
+            data.viewportHeight = viewportHeight;
+            data.deviceWidth = deviceWidth;
+            data.deviceHeight = deviceHeight;
+            data.devicePixelRatio = devicePixelRatio;
+            data.colorBitsPerComponent = colorBitsPerComponent;
+            data.monochromeBitsPerComponent = monochromeBitsPerComponent;
+            data.primaryPointerType = primaryPointerType;
+            data.availablePointerTypes = availablePointerTypes;
+            data.primaryHoverType = primaryHoverType;
+            data.availableHoverTypes = availableHoverTypes;
+            data.defaultFontSize = defaultFontSize;
+            data.threeDEnabled = threeDEnabled;
+            data.strictMode = strictMode;
+            data.mediaType = mediaType.isolatedCopy();
+            data.displayMode = displayMode;
+            return data;
+        }
     };
 
     static PassRefPtrWillBeRawPtr<MediaValuesCached> create();
-    static PassRefPtrWillBeRawPtr<MediaValuesCached> create(Document&);
-    static PassRefPtrWillBeRawPtr<MediaValuesCached> create(LocalFrame*);
-    static PassRefPtrWillBeRawPtr<MediaValuesCached> create(MediaValuesCachedData&);
+    static PassRefPtrWillBeRawPtr<MediaValuesCached> create(const MediaValuesCachedData&);
     PassRefPtrWillBeRawPtr<MediaValues> copy() const override;
-    bool isSafeToSendToAnotherThread() const;
     bool computeLength(double value, CSSPrimitiveValue::UnitType, int& result) const override;
     bool computeLength(double value, CSSPrimitiveValue::UnitType, double& result) const override;
 
     double viewportWidth() const override;
     double viewportHeight() const override;
     int deviceWidth() const override;
     int deviceHeight() const override;
     float devicePixelRatio() const override;
     int colorBitsPerComponent() const override;
     int monochromeBitsPerComponent() const override;
@@ skipping 12 matching lines @@
     void setViewportHeight(double);
 
 protected:
     MediaValuesCached();
     MediaValuesCached(LocalFrame*);
     MediaValuesCached(const MediaValuesCachedData&);
 
     MediaValuesCachedData m_data;
 };
 
+template<> struct CrossThreadCopierBase<false, false, false, MediaValuesCached::MediaValuesCachedData> {

[Yoav Weiss, 2016/02/01 09:29:30]

Where is this used? Is it implicitly called somewhere?

[hiroshige, 2016/02/01 09:42:10]

CrossThreadCopier is called inside threadSafeBind() in HTMLDocumentParser.cpp
(around Line 827).

+    typedef MediaValuesCached::MediaValuesCachedData Type;
+    static Type copy(const MediaValuesCached::MediaValuesCachedData& data) { return data.deepCopy(); }
+};
+
 } // namespace blink
 
 #endif // MediaValuesCached_h