New helper function test::ReadI420Buffer, refactor FrameReader to use it.

webrtc/modules/video_coding/codecs/test/videoprocessor_unittest.cc

 /*
  *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 57 matching lines @@
   ExpectInit();
   VideoProcessorImpl video_processor(
       &encoder_mock_, &decoder_mock_, &frame_reader_mock_, &frame_writer_mock_,
       &packet_manipulator_mock_, config_, &stats_);
   ASSERT_TRUE(video_processor.Init());
 }
 
 TEST_F(VideoProcessorTest, ProcessFrame) {
   ExpectInit();
   EXPECT_CALL(encoder_mock_, Encode(_, _, _)).Times(1);
-  EXPECT_CALL(frame_reader_mock_, ReadFrame(_)).WillOnce(Return(true));
+  EXPECT_CALL(frame_reader_mock_, ReadFrame())
+      .WillOnce(Return(I420Buffer::Create(50, 50)));
   // Since we don't return any callback from the mock, the decoder will not
   // be more than initialized...
   VideoProcessorImpl video_processor(
       &encoder_mock_, &decoder_mock_, &frame_reader_mock_, &frame_writer_mock_,
       &packet_manipulator_mock_, config_, &stats_);
   ASSERT_TRUE(video_processor.Init());
   video_processor.ProcessFrame(0);
 }
 
 }  // namespace test
 }  // namespace webrtc