CC: Fix missing swap-used-incomplete-tile updates

cc/trees/thread_proxy.cc

 // Copyright 2011 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/trees/thread_proxy.h"
 
 #include <string>
 
 #include "base/auto_reset.h"
 #include "base/bind.h"
@@ skipping 526 matching lines @@
   TRACE_EVENT0("cc", "ThreadProxy::SetNeedsRedrawOnImplThread");
   scheduler_on_impl_thread_->SetNeedsRedraw();
 }
 
 void ThreadProxy::SetNeedsRedrawRectOnImplThread(gfx::Rect damage_rect) {
   DCHECK(IsImplThread());
   layer_tree_host_impl_->SetViewportDamage(damage_rect);
   SetNeedsRedrawOnImplThread();
 }
 
-void ThreadProxy::DidSwapUseIncompleteTileOnImplThread() {
+void ThreadProxy::SetSwapUsedIncompleteTileOnImplThread(
+    bool used_incomplete_tile) {
   DCHECK(IsImplThread());
-  TRACE_EVENT0("cc", "ThreadProxy::DidSwapUseIncompleteTileOnImplThread");
-  scheduler_on_impl_thread_->DidSwapUseIncompleteTile();
+  if (used_incomplete_tile) {
+    TRACE_EVENT_INSTANT0(
+        "cc",
+        "ThreadProxy::SetSwapUsedIncompleteTileOnImplThread",
+        TRACE_EVENT_SCOPE_THREAD);
+  }
+  scheduler_on_impl_thread_->SetSwapUsedIncompleteTile(
+    used_incomplete_tile);
 }
 
 void ThreadProxy::DidInitializeVisibleTileOnImplThread() {
   DCHECK(IsImplThread());
   TRACE_EVENT0("cc", "ThreadProxy::DidInitializeVisibleTileOnImplThread");
   scheduler_on_impl_thread_->SetNeedsRedraw();
 }
 
 void ThreadProxy::MainThreadHasStoppedFlinging() {
   DCHECK(IsMainThread());
@@ skipping 519 matching lines @@
                                       readback_request_on_impl_thread_->rect);
       result.did_readback = true;
     }
     readback_request_on_impl_thread_->success = result.did_readback;
     readback_request_on_impl_thread_->completion.Signal();
     readback_request_on_impl_thread_ = NULL;
   } else if (draw_frame) {
     DCHECK(swap_requested);
     result.did_swap = layer_tree_host_impl_->SwapBuffers(frame);
 
-    if (frame.contains_incomplete_tile)
-      DidSwapUseIncompleteTileOnImplThread();
+    // We don't know if we have incomplete tiles if we didn't actually swap.
+    if (result.did_swap) {
+      DCHECK(!frame.has_no_damage);
+      SetSwapUsedIncompleteTileOnImplThread(frame.contains_incomplete_tile);
+    }
   }
 
   // Tell the main thread that the the newly-commited frame was drawn.
   if (next_frame_is_newly_committed_frame_on_impl_thread_) {
     next_frame_is_newly_committed_frame_on_impl_thread_ = false;
     Proxy::MainThreadTaskRunner()->PostTask(
         FROM_HERE,
         base::Bind(&ThreadProxy::DidCommitAndDrawFrame, main_thread_weak_ptr_));
   }
 
@@ skipping 438 matching lines @@
     completion_event_for_commit_held_on_tree_activation_ = NULL;
   }
 
   UpdateBackgroundAnimateTicking();
 
   commit_to_activate_duration_history_.InsertSample(
       base::TimeTicks::HighResNow() - commit_complete_time_);
 }
 
 }  // namespace cc