Fix NULL pointer usage, it is P1 crash bug.

content/browser/android/download_controller_android_impl.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 "content/browser/android/download_controller_android_impl.h"
 
 #include "base/android/jni_android.h"
 #include "base/android/jni_string.h"
 #include "base/bind.h"
 #include "base/logging.h"
@@ skipping 92 matching lines @@
                  render_view_host->GetRoutingID()));
 }
 
 void DownloadControllerAndroidImpl::PrepareDownloadInfo(
     const GlobalRequestID& global_id,
     int render_process_id, int render_view_id) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 
   net::URLRequest* request =
       ResourceDispatcherHostImpl::Get()->GetURLRequest(global_id);
-  DCHECK(request) << "Request to download not found.";
+  if (!request) {
+    LOG(ERROR) << "Request to download not found.";
+    return;
+  }
 
   DownloadInfoAndroid info_android(request);
 
   net::CookieStore* cookie_store = request->context()->cookie_store();
   if (cookie_store) {
     net::CookieMonster* cookie_monster = cookie_store->GetCookieMonster();
     if (cookie_monster) {
       cookie_monster->GetAllCookiesForURLAsync(
           request->url(),
           base::Bind(&DownloadControllerAndroidImpl::CheckPolicyAndLoadCookies,
                      base::Unretained(this), info_android, render_process_id,
                      render_view_id, global_id));
     } else {
       DoLoadCookies(
           info_android, render_process_id, render_view_id, global_id);
     }
   } else {
     // Can't get any cookies, start android download.
     StartAndroidDownload(info_android, render_process_id, render_view_id);
   }
 }
 
 void DownloadControllerAndroidImpl::CheckPolicyAndLoadCookies(
     const DownloadInfoAndroid& info, int render_process_id,
     int render_view_id, const GlobalRequestID& global_id,
     const net::CookieList& cookie_list) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+
   net::URLRequest* request =
       ResourceDispatcherHostImpl::Get()->GetURLRequest(global_id);
-  DCHECK(request) << "Request to download not found.";
+  if (!request) {
+    LOG(ERROR) << "Request to download not found.";
+    return;
+  }
 
   if (request->context()->network_delegate()->CanGetCookies(
       *request, cookie_list)) {
     DoLoadCookies(info, render_process_id, render_view_id, global_id);
   } else {
     StartAndroidDownload(info, render_process_id, render_view_id);
   }
 }
 
 void DownloadControllerAndroidImpl::DoLoadCookies(
     const DownloadInfoAndroid& info, int render_process_id,
     int render_view_id, const GlobalRequestID& global_id) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+
   net::CookieOptions options;
   options.set_include_httponly();
 
   net::URLRequest* request =
       ResourceDispatcherHostImpl::Get()->GetURLRequest(global_id);
-  DCHECK(request) << "Request to download not found.";
+  if (!request) {
+    LOG(ERROR) << "Request to download not found.";
+    return;
+  }
 
   request->context()->cookie_store()->GetCookiesWithOptionsAsync(
       info.url, options,
       base::Bind(&DownloadControllerAndroidImpl::OnCookieResponse,
                  base::Unretained(this), info, render_process_id,
                  render_view_id));
 }
 
 void DownloadControllerAndroidImpl::OnCookieResponse(
     DownloadInfoAndroid download_info,
@@ skipping 163 matching lines @@
     referer = referer_url.spec();
   if (!request->url_chain().empty()) {
     original_url = request->url_chain().front();
     url = request->url_chain().back();
   }
 }
 
 DownloadControllerAndroidImpl::DownloadInfoAndroid::~DownloadInfoAndroid() {}
 
 }  // namespace content