From c052ba992cee6d00e84ee00d434453700fe89731 Mon Sep 17 00:00:00 2001
From: sunnyps <sunnyps@chromium.org>
Date: Mon, 4 May 2015 17:42:29 -0700
Subject: [PATCH] cc: Send BeginFrame to VideoFrameController when added.

When a VideoFrameController starts rendering it has to wait until the
next frame to get a BeginFrame message. This means that it renders
nothing for the first frame if it is able to draw in that frame.

Review URL: https://codereview.chromium.org/1113283002

Cr-Commit-Position: refs/heads/master@{#328238}
---
 cc/layers/video_frame_provider_client_impl.cc |  2 +-
 cc/trees/layer_tree_host_impl.cc              |  2 ++
 cc/trees/layer_tree_host_impl_unittest.cc     | 42 +++++++++++++++++++++++++++
 3 files changed, 45 insertions(+), 1 deletion(-)

diff --git a/cc/layers/video_frame_provider_client_impl.cc b/cc/layers/video_frame_provider_client_impl.cc
index 17bf3e6640c7..5fab4e2f04c4 100644
--- a/cc/layers/video_frame_provider_client_impl.cc
+++ b/cc/layers/video_frame_provider_client_impl.cc
@@ -118,8 +118,8 @@ void VideoFrameProviderClientImpl::StartRendering() {
   TRACE_EVENT0("cc", "VideoFrameProviderClientImpl::StartRendering");
   DCHECK(!rendering_);
   DCHECK(!stopped_);
-  client_->AddVideoFrameController(this);
   rendering_ = true;
+  client_->AddVideoFrameController(this);
 }
 
 void VideoFrameProviderClientImpl::StopRendering() {
diff --git a/cc/trees/layer_tree_host_impl.cc b/cc/trees/layer_tree_host_impl.cc
index f8ffbd3ca173..0af4fbc58cdd 100644
--- a/cc/trees/layer_tree_host_impl.cc
+++ b/cc/trees/layer_tree_host_impl.cc
@@ -3103,6 +3103,8 @@ void LayerTreeHostImpl::AddVideoFrameController(
     VideoFrameController* controller) {
   bool was_empty = video_frame_controllers_.empty();
   video_frame_controllers_.insert(controller);
+  if (current_begin_frame_args_.IsValid())
+    controller->OnBeginFrame(current_begin_frame_args_);
   if (was_empty)
     client_->SetVideoNeedsBeginFrames(true);
 }
diff --git a/cc/trees/layer_tree_host_impl_unittest.cc b/cc/trees/layer_tree_host_impl_unittest.cc
index e1040e3dae73..96fe963999f0 100644
--- a/cc/trees/layer_tree_host_impl_unittest.cc
+++ b/cc/trees/layer_tree_host_impl_unittest.cc
@@ -7894,5 +7894,47 @@ TEST_F(LayerTreeHostImplTest, DoNotRemoveEmptyRootRenderPass) {
   EXPECT_EQ(0u, pass1->quad_list.size());
 }
 
+class FakeVideoFrameController : public VideoFrameController {
+ public:
+  void OnBeginFrame(const BeginFrameArgs& args) override {
+    begin_frame_args_ = args;
+  }
+
+  const BeginFrameArgs& begin_frame_args() { return begin_frame_args_; }
+
+ private:
+  BeginFrameArgs begin_frame_args_;
+};
+
+TEST_F(LayerTreeHostImplTest, AddVideoFrameControllerInsideFrame) {
+  BeginFrameArgs begin_frame_args =
+      CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE);
+  FakeVideoFrameController controller;
+
+  host_impl_->WillBeginImplFrame(begin_frame_args);
+  EXPECT_FALSE(controller.begin_frame_args().IsValid());
+  host_impl_->AddVideoFrameController(&controller);
+  EXPECT_TRUE(controller.begin_frame_args().IsValid());
+  host_impl_->ResetCurrentBeginFrameArgsForNextFrame();
+}
+
+TEST_F(LayerTreeHostImplTest, AddVideoFrameControllerOutsideFrame) {
+  BeginFrameArgs begin_frame_args =
+      CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE);
+  FakeVideoFrameController controller;
+
+  host_impl_->WillBeginImplFrame(begin_frame_args);
+  host_impl_->ResetCurrentBeginFrameArgsForNextFrame();
+
+  EXPECT_FALSE(controller.begin_frame_args().IsValid());
+  host_impl_->AddVideoFrameController(&controller);
+  EXPECT_FALSE(controller.begin_frame_args().IsValid());
+
+  begin_frame_args = CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE);
+  EXPECT_FALSE(controller.begin_frame_args().IsValid());
+  host_impl_->WillBeginImplFrame(begin_frame_args);
+  EXPECT_TRUE(controller.begin_frame_args().IsValid());
+}
+
 }  // namespace
 }  // namespace cc
-- 
2.11.4.GIT