Change WebMediaPlayerMS layers transparency dynamically

content/renderer/media/webmediaplayer_ms_unittest.cc

Index: content/renderer/media/webmediaplayer_ms_unittest.cc
diff --git a/content/renderer/media/webmediaplayer_ms_unittest.cc b/content/renderer/media/webmediaplayer_ms_unittest.cc
index 3920fb0b1b719797f04d15a750aab862549342f9..4551e8d8fa795045e4603d4fcde9831c66b05ffb 100644
--- a/content/renderer/media/webmediaplayer_ms_unittest.cc
+++ b/content/renderer/media/webmediaplayer_ms_unittest.cc
@@ -12,6 +12,7 @@
 #include "content/renderer/render_frame_impl.h"
 #include "media/base/test_helpers.h"
 #include "media/base/video_frame.h"
+#include "third_party/WebKit/public/platform/WebLayer.h"
 #include "third_party/WebKit/public/platform/WebMediaPlayer.h"
 #include "third_party/WebKit/public/platform/WebMediaPlayerClient.h"
 #include "third_party/WebKit/public/platform/WebMediaPlayerSource.h"
@@ -454,6 +455,7 @@ class WebMediaPlayerMSTest
   std::unique_ptr<WebMediaPlayerMS> player_;
   WebMediaPlayerMSCompositor* compositor_;
   ReusableMessageLoopEvent message_loop_controller_;
+  blink::WebLayer* web_layer_;
 
  private:
   // Main function trying to ask WebMediaPlayerMS to submit a frame for
@@ -507,6 +509,7 @@ void WebMediaPlayerMSTest::readyStateChanged() {
 }
 
 void WebMediaPlayerMSTest::setWebLayer(blink::WebLayer* layer) {
+  web_layer_ = layer;
   if (layer)
     compositor_->SetVideoFrameProviderClient(this);
   DoSetWebLayer(!!layer);
@@ -749,6 +752,51 @@ TEST_F(WebMediaPlayerMSTest, RotatedVideoFrame) {
   EXPECT_CALL(*this, DoStopRendering());
 }
 
+// During this test, we check that web layer changes opacity according to the
+// given frames.
+TEST_F(WebMediaPlayerMSTest, OpacityChange) {
+  MockMediaStreamVideoRenderer* provider = LoadAndGetFrameProvider(true);
+
+  // Push one opaque frame.
+  const int kTestBrake = static_cast<int>(FrameType::TEST_BRAKE);
+  static int opaque_tokens[] = {0, kTestBrake};
+  std::vector<int> opaque_timestamps(
+      opaque_tokens, opaque_tokens + sizeof(opaque_tokens) / sizeof(int));
+  provider->QueueFrames(opaque_timestamps, true);
+  EXPECT_CALL(*this, DoSetWebLayer(true));
+  EXPECT_CALL(*this, DoStartRendering());
+  EXPECT_CALL(*this, DoReadyStateChanged(
+                         blink::WebMediaPlayer::ReadyStateHaveMetadata));
+  EXPECT_CALL(*this, DoReadyStateChanged(
+                         blink::WebMediaPlayer::ReadyStateHaveEnoughData));
+  EXPECT_CALL(*this,
+              CheckSizeChanged(gfx::Size(kStandardWidth, kStandardHeight)));
+  message_loop_controller_.RunAndWaitForStatus(
+      media::PipelineStatus::PIPELINE_OK);
+  CHECK(web_layer_);

[mcasas, 2016/09/20 00:35:14]

Don't use CHECK()s in unittests, since they
crash the executable and prevent continuing
with other test cases. Instead, use ASSERT().

[emircan, 2016/09/20 03:00:06]

Done.

+  EXPECT_TRUE(web_layer_->opaque());
+
+  // Push one transparent frame.
+  static int transparent_tokens[] = {33, kTestBrake};
+  std::vector<int> transparent_timestamps(
+      transparent_tokens,
+      transparent_tokens + sizeof(transparent_tokens) / sizeof(int));

[mcasas, 2016/09/20 00:35:14]

|transparent_tokens| is static, so we can use here
arraysize():
std::vector<int> transparent_timestamps(
    transparent_tokens,
    transparent_tokens + arraysize(transparent_tokens));

Also applies to l.764;

[emircan, 2016/09/20 03:00:06]

Done.

+  provider->QueueFrames(transparent_timestamps, false);
+  message_loop_controller_.RunAndWaitForStatus(
+      media::PipelineStatus::PIPELINE_OK);
+  EXPECT_FALSE(web_layer_->opaque());
+
+  // Push another opaque frame.
+  provider->QueueFrames(opaque_timestamps, true);

[mcasas, 2016/09/20 00:35:14]

|opaque_timestamps| has a single frame with a 
timestamp 0, does it mean the class under test
doesn't care about timestamps? If so, we don't
need |transparent_timestamps| and we can use
a dummy static int dummy_tokens{} = {...} etc.

[emircan, 2016/09/20 03:00:06]

We don't care about timestamps, except the TestBrake which helps us check status
between calls. I just wanted to be explicit with defining new frames, but I
agree that using default tokens would make it more clear.

+  message_loop_controller_.RunAndWaitForStatus(
+      media::PipelineStatus::PIPELINE_OK);
+  EXPECT_TRUE(web_layer_->opaque());
+
+  testing::Mock::VerifyAndClearExpectations(this);
+  EXPECT_CALL(*this, DoSetWebLayer(false));
+  EXPECT_CALL(*this, DoStopRendering());
+}
+
 TEST_F(WebMediaPlayerMSTest, BackgroundRendering) {
   // During this test, we will switch to background rendering mode, in which
   // WebMediaPlayerMS::pause does not get called, but