[Android] Fix handling of asset files loading.

chrome/browser/android/android_protocol_adapter.h

 // 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.
 
 #ifndef CHROME_BROWSER_ANDROID_ANDROID_PROTOCOL_ADAPTER_H_
 #define CHROME_BROWSER_ANDROID_ANDROID_PROTOCOL_ADAPTER_H_
 
 #include <jni.h>
 
 #include "net/url_request/url_request.h"
 
+namespace net {
+
+class URLRequestContextGetter;
+
+}
+
+// This class adds support for Android WebView-specific protocol schemes:
+//
+//  - "content:" scheme is used for accessing data from Android content
+//    providers, see http://developer.android.com/guide/topics/providers/
+//      content-provider-basics.html#ContentURIs
+//
+//  - "file:" scheme extension for accessing application assets and resources
+//    (file:///android_asset/ and file:///android_res/), see
+//    http://developer.android.com/reference/android/webkit/
+//      WebSettings.html#setAllowFileAccess(boolean)
+//
 class AndroidProtocolAdapter {
  public:
   static net::URLRequest::ProtocolFactory Factory;
 
-  // Register the protocol factories for all supported Android protocol
-  // schemes.
-  static bool RegisterProtocols(JNIEnv* env);
+  // Register handlers for all supported Android protocol schemes.
+  static void RegisterProtocols(
+      JNIEnv* env, net::URLRequestContextGetter* context_getter);
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(AndroidProtocolAdapter);
 };
 
 #endif  // CHROME_BROWSER_ANDROID_ANDROID_PROTOCOL_ADAPTER_H_