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 bc4fdfbd97e2e233dcc6f960f95a3142e9dc8d60..4f5cdd3e3f23f4628bef2a57e54874a13b048ae1 100644
--- a/content/renderer/renderer_blink_platform_impl.cc
+++ b/content/renderer/renderer_blink_platform_impl.cc
@@ -84,6 +84,7 @@
 #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"
@@ -300,6 +301,12 @@ 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();