Revert of Remove swap ack throttling to regain performance regression on freon

cc/scheduler/scheduler_unittest.cc

Index: cc/scheduler/scheduler_unittest.cc
diff --git a/cc/scheduler/scheduler_unittest.cc b/cc/scheduler/scheduler_unittest.cc
index ec5e1f03c7f05629d8de47c57b094cb464703cfd..52f7c4633b336f752804ee6f70ed98a6f8274725 100644
--- a/cc/scheduler/scheduler_unittest.cc
+++ b/cc/scheduler/scheduler_unittest.cc
@@ -1494,14 +1494,13 @@
   client_->Reset();
 
   // While swap throttled, BeginRetroFrames should trigger BeginImplFrames
-  // and BeginMainFrame.
+  // but not a BeginMainFrame or draw.
   scheduler_->SetNeedsCommit();
   scheduler_->SetNeedsRedraw();
   // Run posted BeginRetroFrame.
   task_runner().RunTasksWhile(client_->ImplFrameDeadlinePending(false));
-  EXPECT_ACTION("WillBeginImplFrame", client_, 0, 3);
-  EXPECT_ACTION("ScheduledActionAnimate", client_, 1, 3);
-  EXPECT_ACTION("ScheduledActionSendBeginMainFrame", client_, 2, 3);
+  EXPECT_ACTION("WillBeginImplFrame", client_, 0, 2);
+  EXPECT_ACTION("ScheduledActionAnimate", client_, 1, 2);
   EXPECT_TRUE(scheduler_->BeginImplFrameDeadlinePending());
   EXPECT_TRUE(client_->needs_begin_frames());
   client_->Reset();
@@ -1515,7 +1514,7 @@
 
   // Take us out of a swap throttled state.
   scheduler_->DidSwapBuffersComplete();
-  EXPECT_NO_ACTION(client_);
+  EXPECT_SINGLE_ACTION("ScheduledActionSendBeginMainFrame", client_);
   EXPECT_TRUE(scheduler_->BeginImplFrameDeadlinePending());
   EXPECT_TRUE(client_->needs_begin_frames());
   client_->Reset();
@@ -1761,14 +1760,13 @@
   EXPECT_FALSE(scheduler_->BeginImplFrameDeadlinePending());
   client_->Reset();
 
-  // While swap throttled, BeginFrames should trigger BeginImplFrames
-  // and BeginMainFrame.
+  // While swap throttled, BeginFrames should trigger BeginImplFrames,
+  // but not a BeginMainFrame or draw.
   scheduler_->SetNeedsCommit();
   scheduler_->SetNeedsRedraw();
   EXPECT_SCOPED(AdvanceFrame());  // Run posted BeginFrame.
-  EXPECT_ACTION("WillBeginImplFrame", client_, 0, 3);
-  EXPECT_ACTION("ScheduledActionAnimate", client_, 1, 3);
-  EXPECT_ACTION("ScheduledActionSendBeginMainFrame", client_, 2, 3);
+  EXPECT_ACTION("WillBeginImplFrame", client_, 0, 2);
+  EXPECT_ACTION("ScheduledActionAnimate", client_, 1, 2);
   EXPECT_TRUE(scheduler_->BeginImplFrameDeadlinePending());
   client_->Reset();
 
@@ -1781,7 +1779,7 @@
 
   // Take us out of a swap throttled state.
   scheduler_->DidSwapBuffersComplete();
-  EXPECT_NO_ACTION(client_);
+  EXPECT_SINGLE_ACTION("ScheduledActionSendBeginMainFrame", client_);
   EXPECT_TRUE(scheduler_->BeginImplFrameDeadlinePending());
   client_->Reset();