From f36e727e15ab6ee2154ad5b2abe5639b1dafdf2e Mon Sep 17 00:00:00 2001
From: brianderson <brianderson@chromium.org>
Date: Wed, 1 Apr 2015 15:06:28 -0700
Subject: [PATCH] cc: Don't background tick for needs redraw

BUG=472237

Review URL: https://codereview.chromium.org/1047343002

Cr-Commit-Position: refs/heads/master@{#323334}
---
 cc/scheduler/scheduler_state_machine.cc          | 10 +++-
 cc/scheduler/scheduler_state_machine_unittest.cc | 60 +++++++++++++++++++++++-
 2 files changed, 68 insertions(+), 2 deletions(-)

diff --git a/cc/scheduler/scheduler_state_machine.cc b/cc/scheduler/scheduler_state_machine.cc
index e3c576306bbe..00076908ae29 100644
--- a/cc/scheduler/scheduler_state_machine.cc
+++ b/cc/scheduler/scheduler_state_machine.cc
@@ -733,7 +733,15 @@ bool SchedulerStateMachine::BeginFrameNeededToAnimateOrDraw() const {
   if (forced_redraw_state_ == FORCED_REDRAW_STATE_WAITING_FOR_DRAW)
     return true;
 
-  return needs_animate_ || needs_redraw_;
+  // TODO(mithro): Remove background animation ticking. crbug.com/371747
+  if (needs_animate_)
+    return true;
+
+  // Only background tick for animations - not draws, which will never happen.
+  if (!visible_)
+    return false;
+
+  return needs_redraw_;
 }
 
 // These are cases where we are very likely to draw soon, but might not
diff --git a/cc/scheduler/scheduler_state_machine_unittest.cc b/cc/scheduler/scheduler_state_machine_unittest.cc
index ba184e569d84..0d94edbb9cc4 100644
--- a/cc/scheduler/scheduler_state_machine_unittest.cc
+++ b/cc/scheduler/scheduler_state_machine_unittest.cc
@@ -104,9 +104,17 @@ class StateMachine : public SchedulerStateMachine {
     return output_surface_state_;
   }
 
+  void SetNeedsCommitForTest(bool needs_commit) {
+    needs_commit_ = needs_commit;
+  }
+
   bool NeedsCommit() const { return needs_commit_; }
 
-  void SetNeedsRedraw(bool b) { needs_redraw_ = b; }
+  void SetNeedsAnimateForTest(bool needs_animate) {
+    needs_animate_ = needs_animate;
+  }
+
+  void SetNeedsRedraw(bool needs_redraw) { needs_redraw_ = needs_redraw; }
 
   void SetNeedsForcedRedrawForTimeout(bool b) {
     forced_redraw_state_ = FORCED_REDRAW_STATE_WAITING_FOR_COMMIT;
@@ -136,6 +144,56 @@ class StateMachine : public SchedulerStateMachine {
   using SchedulerStateMachine::UpdateStateOnCommit;
 };
 
+TEST(SchedulerStateMachineTest, BeginFrameNeeded) {
+  SchedulerSettings default_scheduler_settings;
+  StateMachine state(default_scheduler_settings);
+  state.SetCanStart();
+  EXPECT_ACTION_UPDATE_STATE(
+      SchedulerStateMachine::ACTION_BEGIN_OUTPUT_SURFACE_CREATION)
+  state.CreateAndInitializeOutputSurfaceWithActivatedCommit();
+  state.SetCommitState(SchedulerStateMachine::COMMIT_STATE_IDLE);
+
+  // Don't request BeginFrames if we are idle.
+  state.SetVisible(true);
+  state.SetNeedsRedraw(false);
+  state.SetNeedsAnimateForTest(false);
+  EXPECT_FALSE(state.BeginFrameNeeded());
+
+  // Request BeginFrames if we are ready to draw.
+  state.SetVisible(true);
+  state.SetNeedsRedraw(true);
+  state.SetNeedsAnimateForTest(false);
+  EXPECT_TRUE(state.BeginFrameNeeded());
+
+  // Don't background tick for needs_redraw.
+  state.SetVisible(false);
+  state.SetNeedsRedraw(true);
+  state.SetNeedsAnimateForTest(false);
+  EXPECT_FALSE(state.BeginFrameNeeded());
+
+  // Background tick for animations.
+  state.SetVisible(false);
+  state.SetNeedsRedraw(false);
+  state.SetNeedsAnimateForTest(true);
+  EXPECT_TRUE(state.BeginFrameNeeded());
+
+  // Proactively request BeginFrames when commit is pending.
+  state.SetVisible(true);
+  state.SetNeedsRedraw(false);
+  state.SetNeedsAnimateForTest(false);
+  state.SetNeedsCommitForTest(true);
+  EXPECT_TRUE(state.BeginFrameNeeded());
+
+  // Don't request BeginFrames when commit is pending if
+  // we are currently deferring commits.
+  state.SetVisible(true);
+  state.SetNeedsRedraw(false);
+  state.SetNeedsAnimateForTest(false);
+  state.SetNeedsCommitForTest(true);
+  state.SetDeferCommits(true);
+  EXPECT_FALSE(state.BeginFrameNeeded());
+}
+
 TEST(SchedulerStateMachineTest, TestNextActionBeginsMainFrameIfNeeded) {
   SchedulerSettings default_scheduler_settings;
 
-- 
2.11.4.GIT