Implement the infrastructure of creating WorkerFetchContext in worker global scope.

third_party/WebKit/public/platform/Platform.h

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 37 matching lines @@
 #include "WebLocalizedString.h"
 #include "WebMessagePortChannel.h"
 #include "WebPlatformEventType.h"
 #include "WebSize.h"
 #include "WebSpeechSynthesizer.h"
 #include "WebStorageQuotaCallbacks.h"
 #include "WebStorageQuotaType.h"
 #include "WebString.h"
 #include "WebURLError.h"
 #include "WebVector.h"
+#include "WebWorkerFetchContext.h"
 #include "base/metrics/user_metrics_action.h"
 #include "cc/resources/shared_bitmap.h"
 #include "cc/surfaces/frame_sink_id.h"
 #include "mojo/public/cpp/system/message_pipe.h"
 
 namespace gpu {
 class GpuMemoryBufferManager;
 }
 
 namespace service_manager {
@@ skipping 284 matching lines @@
       int64_t response_time,
       const char* data,
       size_t data_size,
       const blink::WebSecurityOrigin& cache_storage_origin,
       const WebString& cache_storage_cache_name) {}
 
   virtual WebURLError CancelledError(const WebURL&) const {
     return WebURLError();
   }
 
+  // Returns a new WebWorkerFetchContext for a dedicated (or shared) worker.
+  // Returns nullptr if off-main-thread-fetch is disabled.
+  virtual std::unique_ptr<WebWorkerFetchContext> CreateWorkerFetchContext() {
+    return nullptr;
+  }
+
   // Plugins -------------------------------------------------------------
 
   // If refresh is true, then cached information should not be used to
   // satisfy this call. mainFrameOrigin is used by the browser process to
   // filter plugins from the plugin list based on content settings.
   virtual void GetPluginList(bool refresh,
                              const WebSecurityOrigin& main_frame_origin,
                              WebPluginListBuilder*) {}
 
   // Public Suffix List --------------------------------------------------
@@ skipping 342 matching lines @@
  protected:
   Platform();
   virtual ~Platform() {}
 
   WebThread* main_thread_;
 };
 
 }  // namespace blink
 
 #endif