Fix memory leak in tests.

Fixes 2 memory leaks related to GPU accelerated video encoding.
The TaskRunner must run one final time to clean the memory.

BUG=333142

Review URL: https://codereview.chromium.org/134943002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@244422 0039d316-1c4b-4281-b951-d872f2087c98

media/cast/video_sender/external_video_encoder_unittest.cc

@@ -130,6 +130,9 @@ TEST_F(ExternalVideoEncoderTest, EncodePattern30fpsRunningOutOfAck) {
                                                  frame_encoded_callback));
     task_runner_->RunTasks();
   }
+  // We need to run the task to cleanup the GPU instance.
+  video_encoder_.reset(NULL);
+  task_runner_->RunTasks();
 }
 
 }  // namespace cast

media/cast/video_sender/video_sender_unittest.cc

@@ -129,6 +129,10 @@ TEST_F(VideoSenderTest, ExternalEncoder) {
   video_sender_->InsertRawVideoFrame(video_frame, capture_time);
 
   task_runner_->RunTasks();
+
+  // We need to run the task to cleanup the GPU instance.
+  video_sender_.reset(NULL);
+  task_runner_->RunTasks();
 }
 
 TEST_F(VideoSenderTest, RtcpTimer) {