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..bd7f8e0b8b60e24603e3ea2f8fa60a24268efeb2 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 (or shared) 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 0; }

[kinuko, 2017/04/19 11:08:14]

nit: return nullptr for new code

[horo, 2017/04/19 13:52:27]

Done.

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