Merge 167537 - Use message passing for BeginFrameAndCommitState and clean up forced commit logic

cc/scheduler_state_machine.h

Index: cc/scheduler_state_machine.h
===================================================================
--- cc/scheduler_state_machine.h	(revision 168090)
+++ cc/scheduler_state_machine.h	(working copy)
@@ -93,6 +93,8 @@
 
     // As setNeedsCommit(), but ensures the beginFrame will definitely happen even if
     // we are not visible.
+    // After this call we expect to go through the forced commit flow and then return
+    // to waiting for a non-forced beginFrame to finish.
     void setNeedsForcedCommit();
 
     // Call this only in response to receiving an ACTION_BEGIN_FRAME
@@ -144,6 +146,7 @@
     bool m_needsForcedRedrawAfterNextCommit;
     bool m_needsCommit;
     bool m_needsForcedCommit;
+    bool m_expectImmediateBeginFrame;
     bool m_mainThreadNeedsLayerTextures;
     bool m_insideVSync;
     bool m_visible;