Add UMA to estimate deroppable memory usage of encoded data size in Resources

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

Index: third_party/WebKit/Source/core/fetch/Resource.h
diff --git a/third_party/WebKit/Source/core/fetch/Resource.h b/third_party/WebKit/Source/core/fetch/Resource.h
index 360d442c059804a5b008a471faf819f5b2c33f04..0fde41972378976849fa056bcba8380ad3378712 100644
--- a/third_party/WebKit/Source/core/fetch/Resource.h
+++ b/third_party/WebKit/Source/core/fetch/Resource.h
@@ -402,6 +402,8 @@ class CORE_EXPORT Resource : public GarbageCollectedFinalized<Resource>,
         : AutoReset(&resource->m_isAddRemoveClientProhibited, true) {}
   };
 
+  bool isReloadable() const;

[yhirano, 2016/11/15 10:21:55]

What does this method mean?

[hajimehoshi, 2016/11/15 10:50:07]

This returns true when the resource can be reloaded. For example, if the image
is used as CSS background, it is difficult to load the encoded data from the
disk cache in the current implementation, and this function returns false in
this case.

+
  private:
   class ResourceCallback;
   class CachedMetadataHandlerImpl;