[Android] Use resource throttle instead of HandleExternalProtocol.

chrome/browser/renderer_host/chrome_resource_dispatcher_host_delegate.cc

 // Copyright (c) 2012 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 "chrome/browser/renderer_host/chrome_resource_dispatcher_host_delegate.h"
 
 #include <string>
 
 #include "base/base64.h"
 #include "base/logging.h"
@@ skipping 235 matching lines @@
 
   return false;
 }
 
 ResourceDispatcherHostLoginDelegate*
     ChromeResourceDispatcherHostDelegate::CreateLoginDelegate(
         net::AuthChallengeInfo* auth_info, net::URLRequest* request) {
   return CreateLoginPrompt(auth_info, request);
 }
 
-void ChromeResourceDispatcherHostDelegate::HandleExternalProtocol(
+bool ChromeResourceDispatcherHostDelegate::HandleExternalProtocol(
     const GURL& url, int child_id, int route_id) {
+#if defined(OS_ANDROID)
+  // Android use a resource throttle to handle external as well as internal
+  // protocols.
+  return false;
+#else
   BrowserThread::PostTask(
       BrowserThread::UI, FROM_HERE,
       base::Bind(&ExternalProtocolHandler::LaunchUrl, url, child_id, route_id));
+  return true;
+#endif
 }
 
 void ChromeResourceDispatcherHostDelegate::AppendStandardResourceThrottles(
     const net::URLRequest* request,
     content::ResourceContext* resource_context,
     int child_id,
     int route_id,
     ResourceType::Type resource_type,
     ScopedVector<content::ResourceThrottle>* throttles) {
 #if defined(ENABLE_SAFE_BROWSING)
@@ skipping 199 matching lines @@
   if (base::Base64Encode(serialized, &hashed)) {
     // If successful, swap the header value with the new one.
     // Note that the list of IDs and the header could be temporarily out of sync
     // if IDs are added as the header is recreated. The receiving servers are OK
     // with such descrepancies.
     variation_ids_header_ = hashed;
   } else {
     DVLOG(1) << "Failed to base64 encode Variation IDs value: " << serialized;
   }
 }