Revert 285479 "Make DataSource::Stop() synchronous."

trunk/src/content/renderer/media/buffered_data_source_unittest.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 "base/bind.h"
 #include "base/message_loop/message_loop.h"
 #include "content/public/common/url_constants.h"
 #include "content/renderer/media/buffered_data_source.h"
 #include "content/renderer/media/test_response_generator.h"
 #include "content/test/mock_webframeclient.h"
@@ skipping 160 matching lines @@
   // Stops any active loaders and shuts down the data source.
   //
   // This typically happens when the page is closed and for our purposes is
   // appropriate to do when tearing down a test.
   void Stop() {
     if (data_source_->loading()) {
       loader()->didFail(url_loader(), response_generator_->GenerateError());
       message_loop_.RunUntilIdle();
     }
 
-    data_source_->Stop();
+    data_source_->Stop(media::NewExpectedClosure());
     message_loop_.RunUntilIdle();
   }
 
   void ExpectCreateResourceLoader() {
     EXPECT_CALL(*data_source_, CreateResourceLoader(_, _))
         .WillOnce(Invoke(data_source_.get(),
                          &MockBufferedDataSource::CreateMockResourceLoader));
     message_loop_.RunUntilIdle();
   }
 
@@ skipping 306 matching lines @@
 }
 
 TEST_F(BufferedDataSourceTest, File_Successful) {
   InitializeWithFileResponse();
 
   EXPECT_TRUE(data_source_->loading());
   EXPECT_FALSE(data_source_->IsStreaming());
   Stop();
 }
 
+static void SetTrue(bool* value) {
+  *value = true;
+}
+
+// This test makes sure that Stop() does not require a task to run on
+// |message_loop_| before it calls its callback. This prevents accidental
+// introduction of a pipeline teardown deadlock. The pipeline owner blocks
+// the render message loop while waiting for Stop() to complete. Since this
+// object runs on the render message loop, Stop() will not complete if it
+// requires a task to run on the the message loop that is being blocked.
+TEST_F(BufferedDataSourceTest, StopDoesNotUseMessageLoopForCallback) {
+  InitializeWith206Response();
+
+  // Stop() the data source, using a callback that lets us verify that it was
+  // called before Stop() returns. This is to make sure that the callback does
+  // not require |message_loop_| to execute tasks before being called.
+  bool stop_done_called = false;
+  EXPECT_TRUE(data_source_->loading());
+  data_source_->Stop(base::Bind(&SetTrue, &stop_done_called));
+
+  // Verify that the callback was called inside the Stop() call.
+  EXPECT_TRUE(stop_done_called);
+  message_loop_.RunUntilIdle();
+}
+
 TEST_F(BufferedDataSourceTest, StopDuringRead) {
   InitializeWith206Response();
 
   uint8 buffer[256];
   data_source_->Read(0, arraysize(buffer), buffer, base::Bind(
       &BufferedDataSourceTest::ReadCallback, base::Unretained(this)));
 
   // The outstanding read should fail before the stop callback runs.
   {
     InSequence s;
     EXPECT_CALL(*this, ReadCallback(media::DataSource::kReadError));
-    data_source_->Stop();
+    data_source_->Stop(media::NewExpectedClosure());
   }
   message_loop_.RunUntilIdle();
 }
 
 TEST_F(BufferedDataSourceTest, DefaultValues) {
   InitializeWith206Response();
 
   // Ensure we have sane values for default loading scenario.
   EXPECT_EQ(AUTO, preload());
   EXPECT_EQ(BufferedResourceLoader::kCapacityDefer, defer_strategy());
@@ skipping 241 matching lines @@
   data_source_->MediaIsPlaying();
   EXPECT_EQ(BufferedResourceLoader::kCapacityDefer, defer_strategy());
   set_might_be_reused_from_cache_in_future(false);
   data_source_->MediaIsPaused();
   EXPECT_EQ(BufferedResourceLoader::kCapacityDefer, defer_strategy());
 
   Stop();
 }
 
 }  // namespace content