[Android WebView] Call shouldInterceptRequest on a background thread

android_webview/browser/aw_request_interceptor.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 "android_webview/browser/aw_request_interceptor.h"
-
-#include "android_webview/browser/aw_contents_io_thread_client.h"
-#include "android_webview/browser/aw_web_resource_response.h"
-#include "base/android/jni_string.h"
-#include "base/memory/scoped_ptr.h"
-#include "content/public/browser/browser_thread.h"
-#include "content/public/browser/render_view_host.h"
-#include "content/public/browser/resource_request_info.h"
-#include "net/url_request/url_request.h"
-#include "net/url_request/url_request_context.h"
-#include "net/url_request/url_request_context_getter.h"
-#include "net/url_request/url_request_job.h"
-
-using content::BrowserThread;
-using content::RenderViewHost;
-using content::ResourceRequestInfo;
-
-namespace android_webview {
-
-namespace {
-
-const void* const kRequestAlreadyQueriedDataKey =
-    &kRequestAlreadyQueriedDataKey;
-
-}  // namespace
-
-AwRequestInterceptor::AwRequestInterceptor() {
-}
-
-AwRequestInterceptor::~AwRequestInterceptor() {
-}
-
-scoped_ptr<AwWebResourceResponse>
-AwRequestInterceptor::QueryForAwWebResourceResponse(
-    net::URLRequest* request) const {
-  DCHECK_CURRENTLY_ON(BrowserThread::IO);
-  int render_process_id, render_frame_id;
-  if (!ResourceRequestInfo::GetRenderFrameForRequest(
-      request, &render_process_id, &render_frame_id))
-    return scoped_ptr<AwWebResourceResponse>();
-
-  scoped_ptr<AwContentsIoThreadClient> io_thread_client =
-      AwContentsIoThreadClient::FromID(render_process_id, render_frame_id);
-
-  if (!io_thread_client.get())
-    return scoped_ptr<AwWebResourceResponse>();
-
-  GURL referrer(request->referrer());
-  if (referrer.is_valid() &&
-      (!request->is_pending() || request->is_redirecting())) {
-    request->SetExtraRequestHeaderByName(net::HttpRequestHeaders::kReferer,
-                                         referrer.spec(), true);
-  }
-  return io_thread_client->ShouldInterceptRequest(request).Pass();
-}
-
-net::URLRequestJob* AwRequestInterceptor::MaybeInterceptRequest(
-    net::URLRequest* request,
-    net::NetworkDelegate* network_delegate) const {
-  DCHECK_CURRENTLY_ON(BrowserThread::IO);
-
-  // See if we've already found out the aw_web_resource_response for this
-  // request.
-  // This is done not only for efficiency reasons, but also for correctness
-  // as it is possible for the Interceptor chain to be invoked more than once
-  // in which case we don't want to query the embedder multiple times.
-  // Note: The Interceptor chain is not invoked more than once if we create a
-  // URLRequestJob in this method, so this is only caching negative hits.
-  if (request->GetUserData(kRequestAlreadyQueriedDataKey))
-    return NULL;
-  request->SetUserData(kRequestAlreadyQueriedDataKey,
-                       new base::SupportsUserData::Data());
-
-  scoped_ptr<AwWebResourceResponse> aw_web_resource_response =
-      QueryForAwWebResourceResponse(request);
-
-  if (!aw_web_resource_response)
-    return NULL;
-
-  // The newly created job will own the AwWebResourceResponse.
-  return AwWebResourceResponse::CreateJobFor(
-      aw_web_resource_response.Pass(), request, network_delegate);
-}
-
-}  // namespace android_webview