Fixed some crashes when playing media from the blob URL.

content/browser/media/android/media_resource_getter_impl.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 "content/browser/media/android/media_resource_getter_impl.h"
 
 #include "base/android/jni_android.h"
 #include "base/android/jni_string.h"
 #include "base/bind.h"
 #include "base/path_service.h"
 #include "base/threading/sequenced_worker_pool.h"
 #include "content/browser/child_process_security_policy_impl.h"
 #include "content/browser/fileapi/browser_file_system_helper.h"
 #include "content/browser/fileapi/chrome_blob_storage_context.h"
+#include "content/browser/resource_context_impl.h"
 #include "content/public/browser/browser_context.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/content_browser_client.h"
 #include "content/public/common/content_client.h"
 #include "content/public/common/url_constants.h"
 #include "jni/MediaResourceGetter_jni.h"
 #include "media/base/android/media_url_interceptor.h"
 #include "net/base/auth.h"
 #include "net/cookies/cookie_monster.h"
 #include "net/cookies/cookie_store.h"
@@ skipping 12 matching lines @@
 
 static void ReturnResultOnUIThread(
     const base::Callback<void(const std::string&)>& callback,
     const std::string& result) {
   BrowserThread::PostTask(
       BrowserThread::UI, FROM_HERE, base::Bind(callback, result));
 }
 
 static void RequestPlatformPathFromBlobURL(
     const GURL& url,
-    BrowserContext* browser_context,
+    ResourceContext* resource_context,
     const base::Callback<void(const std::string&)>& callback) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
-  ChromeBlobStorageContext* context =
-      ChromeBlobStorageContext::GetFor(browser_context);
+  ChromeBlobStorageContext* blob_storage_context =
+      GetChromeBlobStorageContextForResourceContext(resource_context);
+
   scoped_ptr<storage::BlobDataHandle> handle =
-      context->context()->GetBlobDataFromPublicURL(url);
+      blob_storage_context->context()->GetBlobDataFromPublicURL(url);
+  if (!handle) {
+    // There are plenty of cases where handle can be empty. The most trivial is
+    // when JS has aready revoked the given blob URL via URL.revokeObjectURL
+    ReturnResultOnUIThread(callback, std::string());
+    return;
+  }
   storage::BlobData* data = handle->data();
   if (!data) {
-    ReturnResultOnUIThread(callback, "");
+    ReturnResultOnUIThread(callback, std::string());
     NOTREACHED();
     return;
   }
   const std::vector<storage::BlobData::Item> items = data->items();
 
   // TODO(qinmin): handle the case when the blob data is not a single file.
   DLOG_IF(WARNING, items.size() != 1u)
       << "More than one blob data are present: " << items.size();
   ReturnResultOnUIThread(callback, items[0].path().value());
 }
@@ skipping 255 matching lines @@
 
   GetPlatformPathCB cb =
       base::Bind(&MediaResourceGetterImpl::GetPlatformPathCallback,
                  weak_factory_.GetWeakPtr(),
                  callback);
 
   if (url.SchemeIs(url::kBlobScheme)) {
     BrowserThread::PostTask(
         BrowserThread::IO,
         FROM_HERE,
-        base::Bind(&RequestPlatformPathFromBlobURL, url, browser_context_, cb));
+        base::Bind(&RequestPlatformPathFromBlobURL, url,
+                   browser_context_->GetResourceContext(), cb));
     return;
   }
 
   scoped_refptr<storage::FileSystemContext> context(file_system_context_);
   BrowserThread::PostTask(
       BrowserThread::FILE,
       FROM_HERE,
       base::Bind(&RequestPlaformPathFromFileSystemURL, url, render_process_id_,
                  context, cb));
 }
@@ skipping 23 matching lines @@
       FROM_HERE,
       base::Bind(&GetMediaMetadataFromFd, fd, offset, size, callback));
 }
 
 // static
 bool MediaResourceGetterImpl::RegisterMediaResourceGetter(JNIEnv* env) {
   return RegisterNativesImpl(env);
 }
 
 }  // namespace content