Supply empty frames until codec is done with top-off.

remoting/codec/codec_test.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 <deque>
 #include <stdlib.h>
 
 #include "base/bind.h"
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
@@ skipping 266 matching lines @@
       }
 
       // Pass some empty frames through the encoder.
       for (int i = 0; i < 10; ++i) {
         TestEncodingRects(encoder, &tester, frame.get(), nullptr, 0);
       }
     }
   }
 }
 
-void TestVideoEncoderEmptyFrames(VideoEncoder* encoder, int topoff_frames) {
+void TestVideoEncoderEmptyFrames(VideoEncoder* encoder,
+                                 int max_topoff_frames) {
   const DesktopSize kSize(640, 480);
   scoped_ptr<DesktopFrame> frame(PrepareFrame(kSize));
 
   frame->mutable_updated_region()->SetRect(
       webrtc::DesktopRect::MakeSize(kSize));
   EXPECT_TRUE(encoder->Encode(*frame));
 
+  int topoff_frames = 0;
   frame->mutable_updated_region()->Clear();
-  for (int i=0; i < topoff_frames; ++i) {
-    EXPECT_TRUE(encoder->Encode(*frame));
+  for (int i = 0; i < max_topoff_frames + 1; ++i) {
+    if (!encoder->Encode(*frame))
+      break;
+    topoff_frames++;
   }
 
-  EXPECT_FALSE(encoder->Encode(*frame));
+  // If top-off is enabled then our random frame contents should always
+  // trigger it, so expect at least one top-off frame - strictly, though,
+  // an encoder may not always need to top-off.
+  EXPECT_GE(topoff_frames, max_topoff_frames ? 1 : 0);
+  EXPECT_LE(topoff_frames, max_topoff_frames);
 }
 
 static void TestEncodeDecodeRects(VideoEncoder* encoder,
                                   VideoEncoderTester* encoder_tester,
                                   VideoDecoderTester* decoder_tester,
                                   DesktopFrame* frame,
                                   const DesktopRect* rects, int count) {
   frame->mutable_updated_region()->Clear();
   for (int i = 0; i < count; ++i) {
     frame->mutable_updated_region()->AddRect(rects[i]);
@@ skipping 131 matching lines @@
 
     if (frame_count >= kWarmUpFrameCount) {
       elapsed = base::TimeTicks::Now() - start_time;
     }
   }
 
   return (frame_count * base::TimeDelta::FromSeconds(1)) / elapsed;
 }
 
 }  // namespace remoting