Implement the infrastructure of creating WorkerFetchContext in worker global scope.

third_party/WebKit/public/web/WebFrameClient.h

Index: third_party/WebKit/public/web/WebFrameClient.h
diff --git a/third_party/WebKit/public/web/WebFrameClient.h b/third_party/WebKit/public/web/WebFrameClient.h
index 2e660fb82d3f81565ff2c00f730914707f93a8c1..897bc8b2aaf537be8e303debd5ccc9a5bab05f55 100644
--- a/third_party/WebKit/public/web/WebFrameClient.h
+++ b/third_party/WebKit/public/web/WebFrameClient.h
@@ -99,6 +99,7 @@ class WebURL;
 class WebURLResponse;
 class WebUserMediaClient;
 class WebWorkerContentSettingsClientProxy;
+class WebWorkerFetchContext;
 struct WebColorSuggestion;
 struct WebConsoleMessage;
 struct WebContextMenuData;
@@ -146,6 +147,11 @@ class BLINK_EXPORT WebFrameClient {
     return 0;
   }
 
+  // Returns a new WebWorkerFetchContext for a dedicated worker. Ownership of
+  // the returned object is transferred to the caller. This is used only when
+  // off-main-thread-fetch is enabled.
+  virtual WebWorkerFetchContext* CreateWorkerFetchContext() { return nullptr; }

[kinuko, 2017/04/20 04:08:14]

Could we make this return std::unique_ptr<>

[nhiroki, 2017/04/20 04:16:07]

How about returning std::unique_ptr<WebWorkerFetchContext>?

[horo, 2017/04/20 08:35:43]

Done.

+
   // Create a new WebPopupMenu. In the "createExternalPopupMenu" form, the
   // client is responsible for rendering the contents of the popup menu.
   virtual WebExternalPopupMenu* CreateExternalPopupMenu(