Implement frame attribution (FrameBlamer)

content/renderer/renderer_blink_platform_impl.cc

Index: content/renderer/renderer_blink_platform_impl.cc
diff --git a/content/renderer/renderer_blink_platform_impl.cc b/content/renderer/renderer_blink_platform_impl.cc
index 2de292d848d739fdf503749f8688b0869fbddc17..c35e3aa0743dfb32cd952e24955680f06bd94e04 100644
--- a/content/renderer/renderer_blink_platform_impl.cc
+++ b/content/renderer/renderer_blink_platform_impl.cc
@@ -83,6 +83,7 @@
 #include "media/filters/stream_parser_factory.h"
 #include "storage/common/database/database_identifier.h"
 #include "storage/common/quota/quota_types.h"
+#include "third_party/WebKit/public/platform/BlameContext.h"
 #include "third_party/WebKit/public/platform/FilePathConversion.h"
 #include "third_party/WebKit/public/platform/URLConversion.h"
 #include "third_party/WebKit/public/platform/WebBlobRegistry.h"
@@ -299,6 +300,12 @@ blink::WebThread* RendererBlinkPlatformImpl::currentThread() {
   return BlinkPlatformImpl::currentThread();
 }
 
+blink::BlameContext* RendererBlinkPlatformImpl::threadBlameContext() {
+  if (!main_thread_->isCurrentThread())
+    return nullptr;
+  return RenderThreadImpl::current()->blame_context();
+}
+
 blink::WebClipboard* RendererBlinkPlatformImpl::clipboard() {
   blink::WebClipboard* clipboard =
       GetContentClient()->renderer()->OverrideWebClipboard();