cc: Add readback and forced draw states to the Scheduler.

Readback doesn't have all its steps synchronized properly with
impl side painting enabled. This patch prevents the readback
commit from being swapped to screen and avoids using non-readback
commits for readback by adding a SynchronousReadbackState.

This patch also gives forced draws due to checkerboarding its
own ForcedReadback state that behaves independently of readback.

Previously readback and forced draws shared drawing mechanisms,
but we want readbacks to occur ASAP while we want forced draws
to occur inline with the normal frame scheduling.

BUG=276082

Review URL: https://chromiumcodereview.appspot.com/23503003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@221854 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 2 insertions, 0 deletions

diff --git a/cc/test/layer_tree_test.h b/cc/test/layer_tree_test.h
index c6a3f4d..5ac3f85 100644
--- a/cc/test/layer_tree_test.h
+++ b/cc/test/layer_tree_test.h
@@ -112,6 +112,7 @@ class LayerTreeTest : public testing::Test, public TestHooks {
   void PostAddAnimationToMainThread(Layer* layer_to_receive_animation);
   void PostAddInstantAnimationToMainThread(Layer* layer_to_receive_animation);
   void PostSetNeedsCommitToMainThread();
+  void PostReadbackToMainThread();
   void PostAcquireLayerTextures();
   void PostSetNeedsRedrawToMainThread();
   void PostSetNeedsRedrawRectToMainThread(gfx::Rect damage_rect);
@@ -132,6 +133,7 @@ class LayerTreeTest : public testing::Test, public TestHooks {
   virtual void DispatchAddInstantAnimation(Layer* layer_to_receive_animation);
   virtual void DispatchAddAnimation(Layer* layer_to_receive_animation);
   void DispatchSetNeedsCommit();
+  void DispatchReadback();
   void DispatchAcquireLayerTextures();
   void DispatchSetNeedsRedraw();
   void DispatchSetNeedsRedrawRect(gfx::Rect damage_rect);