cc: Properly detect when child Surfaces idle

cc/surfaces/display_scheduler_unittest.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "cc/surfaces/display_scheduler.h"
 
 #include "base/logging.h"
 #include "base/test/null_task_runner.h"
 #include "base/trace_event/trace_event.h"
 #include "cc/output/begin_frame_args.h"
@@ skipping 98 matching lines @@
   SurfaceId root_surface_id(1);
   BeginFrameForTest();
   EXPECT_LT(now_src().Now(),
             scheduler_->DesiredBeginFrameDeadlineTimeForTest());
   scheduler_->EntireDisplayDamaged(root_surface_id);
   EXPECT_GE(now_src().Now(),
             scheduler_->DesiredBeginFrameDeadlineTimeForTest());
 }
 
 TEST_F(DisplaySchedulerTest, SurfaceDamaged) {
+  SurfaceId root_surface_id(0);
   SurfaceId sid1(1);
   SurfaceId sid2(2);
 
+  // Set the root surface
+  scheduler_->EntireDisplayDamaged(root_surface_id);
+
   // Get scheduler to detect surface 1 as active by drawing
   // two frames in a row with damage from surface 1.
   BeginFrameForTest();
   scheduler_->SurfaceDamaged(sid1);
   scheduler_->BeginFrameDeadlineForTest();
   BeginFrameForTest();
   scheduler_->SurfaceDamaged(sid1);
   scheduler_->BeginFrameDeadlineForTest();
 
   // Damage only from surface 2 (inactive) does not trigger deadline early.
@@ skipping 18 matching lines @@
   BeginFrameForTest();
   EXPECT_LT(now_src().Now(),
             scheduler_->DesiredBeginFrameDeadlineTimeForTest());
   scheduler_->SurfaceDamaged(sid1);
   EXPECT_LT(now_src().Now(),
             scheduler_->DesiredBeginFrameDeadlineTimeForTest());
   scheduler_->SurfaceDamaged(sid2);
   EXPECT_GE(now_src().Now(),
             scheduler_->DesiredBeginFrameDeadlineTimeForTest());
   scheduler_->BeginFrameDeadlineForTest();
+
+  // Make the system idle
+  BeginFrameForTest();
+  scheduler_->BeginFrameDeadlineForTest();
+  BeginFrameForTest();
+  scheduler_->BeginFrameDeadlineForTest();
+
+  // Deadline should trigger early if child surfaces are idle and
+  // we get damage on the root surface.
+  BeginFrameForTest();
+  EXPECT_LT(now_src().Now(),
+            scheduler_->DesiredBeginFrameDeadlineTimeForTest());
+  scheduler_->SurfaceDamaged(root_surface_id);
+  EXPECT_GE(now_src().Now(),
+            scheduler_->DesiredBeginFrameDeadlineTimeForTest());
+  scheduler_->BeginFrameDeadlineForTest();
 }
 
 TEST_F(DisplaySchedulerTest, OutputSurfaceLost) {
   SurfaceId sid1(1);
 
   // DrawAndSwap normally.
   BeginFrameForTest();
   EXPECT_LT(now_src().Now(),
             scheduler_->DesiredBeginFrameDeadlineTimeForTest());
   EXPECT_EQ(0, client_->draw_and_swap_count());
@@ skipping 142 matching lines @@
 
   scheduler_->SetRootSurfaceResourcesLocked(true);
   EXPECT_EQ(count++, scheduler_->scheduler_begin_frame_deadline_count());
 
   scheduler_->OutputSurfaceLost();
   EXPECT_EQ(count++, scheduler_->scheduler_begin_frame_deadline_count());
 }
 
 }  // namespace
 }  // namespace cc