Explicitly clear the image in the first updateImage() call

third_party/WebKit/Source/core/fetch/ImageResource.h

Index: third_party/WebKit/Source/core/fetch/ImageResource.h
diff --git a/third_party/WebKit/Source/core/fetch/ImageResource.h b/third_party/WebKit/Source/core/fetch/ImageResource.h
index f28b46eea73b69e73c84c22c601f033610d89870..152777e57229f666d6fda7066f26041a661f0bf7 100644
--- a/third_party/WebKit/Source/core/fetch/ImageResource.h
+++ b/third_party/WebKit/Source/core/fetch/ImageResource.h
@@ -24,6 +24,7 @@
 #define ImageResource_h
 
 #include "core/CoreExport.h"
+#include "core/fetch/ImageResourceContent.h"

[hajimehoshi, 2016/12/06 07:26:00]

I couldn't find this file.

 #include "core/fetch/MultipartImageResourceParser.h"
 #include "core/fetch/Resource.h"
 #include <memory>
@@ -34,7 +35,6 @@ class FetchRequest;
 class ResourceClient;
 class ResourceFetcher;
 class SecurityOrigin;
-class ImageResourceContent;
 
 // ImageResource is the resource-related part of image loading.
 // Image-related things (blink::Image and ImageResourceObserver) are handled by
@@ -135,12 +135,23 @@ class CORE_EXPORT ImageResource final
   void destroyDecodedDataIfPossible() override;
   void destroyDecodedDataForFailedRevalidation() override;
 
+  // When ClearImageOption is KeepExistingImage but this is the first
+  // updateImage() call, then ClearExistingImage is used instead to enforce
+  // new image creation.
+  void updateImage(PassRefPtr<SharedBuffer>,
+                   ImageResourceContent::ClearImageOption,
+                   bool allDataReceived);
   void flushImageIfNeeded(TimerBase*);
 
   bool willPaintBrokenImage() const;
 
   Member<ImageResourceContent> m_content;
 
+  // Indicates whether updateImage() is called for this resource, or for this
+  // part (in case of multipart images), and is used for enforcing creation of
+  // new blink::Image in ImageResourceContent for the first updateImage().
+  bool m_isUpdateImageCalled = false;
+
   float m_devicePixelRatioHeaderValue;
 
   Member<MultipartImageResourceParser> m_multipartParser;