Begin to enable extension APIs in Extension Service Worker.

extensions/browser/extension_function.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "extensions/browser/extension_function.h"
 
 #include <utility>
 
 #include "base/logging.h"
 #include "base/macros.h"
@@ skipping 425 matching lines @@
   BrowserThread::DeleteOnUIThread::Destruct(this);
 }
 
 content::RenderViewHost*
 UIThreadExtensionFunction::render_view_host_do_not_use() const {
   return render_frame_host_ ? render_frame_host_->GetRenderViewHost() : nullptr;
 }
 
 void UIThreadExtensionFunction::SetRenderFrameHost(
     content::RenderFrameHost* render_frame_host) {
+  // An extension function from Service Worker does not have a RenderFrameHost.
+  if (!render_frame_host)
+    return;
   DCHECK_NE(render_frame_host_ == nullptr, render_frame_host == nullptr);
   render_frame_host_ = render_frame_host;
   tracker_.reset(
       render_frame_host ? new RenderFrameHostTracker(this) : nullptr);
 }
 
 content::WebContents* UIThreadExtensionFunction::GetAssociatedWebContents() {
   content::WebContents* web_contents = NULL;
   if (dispatcher())
     web_contents = dispatcher()->GetAssociatedWebContents();
@@ skipping 103 matching lines @@
 ExtensionFunction::ResponseAction SyncIOThreadExtensionFunction::Run() {
   return RespondNow(RunSync() ? ArgumentList(std::move(results_))
                               : Error(error_));
 }
 
 // static
 bool SyncIOThreadExtensionFunction::ValidationFailure(
     SyncIOThreadExtensionFunction* function) {
   return false;
 }