Remove cc::LayerTreeHostImpl::IsContextLost

cc/trees/single_thread_proxy.cc

Index: cc/trees/single_thread_proxy.cc
diff --git a/cc/trees/single_thread_proxy.cc b/cc/trees/single_thread_proxy.cc
index f4007330011329151558931a8b3955779ab44ab3..1adb2706897e99d67ea81edd139531fc380b834f 100644
--- a/cc/trees/single_thread_proxy.cc
+++ b/cc/trees/single_thread_proxy.cc
@@ -316,6 +316,11 @@ void SingleThreadProxy::DidLoseOutputSurfaceOnImplThread() {
   // Cause a commit so we can notice the lost context.
   SetNeedsCommitOnImplThread();

[danakj, 2014/08/15 17:45:15]

Should this move to STP::DidLoseOutputSurface (ie happen at the same time we
tell the LTH)?

[dneto, 2014/08/15 18:17:17]

Actually we might just remove this, since LTH::DidLoseOutputSurface calls
LTH::SetNeedsCommit which then comes back into proxy_->SetNeedsCommit which then
calls client_->ScheduleComposite

That's the same effect as SetNeedsCommitOnImplThread.
I'll see if that works without too much mayhem.

[danakj, 2014/08/15 18:18:10]

Oh good SGTM

   client_->DidAbortSwapBuffers();
+  // Tell the LayerTreeHost, but not right away.
+  Proxy::MainThreadTaskRunner()->PostTask(
+      FROM_HERE,
+      base::Bind(&LayerTreeHost::DidLoseOutputSurface,

[danakj, 2014/08/15 17:45:15]

Can you add a SingleThreadProxy::DidLoseOutputSurface() and post that instead,
then have that call LTH?

You'll also want to add a "base::WeakPtrFactory<SingleThreadProxy>
weak_factory_;" to this class and post the task with that weak factory. You can
steal that from
https://codereview.chromium.org/134623005/diff/2230001/cc/trees/single_thread...

[dneto, 2014/08/15 17:58:20]

Good point.  Yes, I can do this.

+                 base::Unretained(layer_tree_host_)));
 }
 
 void SingleThreadProxy::DidSwapBuffersOnImplThread() {
@@ -433,12 +438,13 @@ bool SingleThreadProxy::DoComposite(base::TimeTicks frame_begin_time,
         layer_tree_host_impl_->CurrentFrameTimeTicks());
     UpdateBackgroundAnimateTicking();
 
-    if (!layer_tree_host_impl_->IsContextLost()) {
-      layer_tree_host_impl_->PrepareToDraw(frame);
+    DrawResult draw_result = layer_tree_host_impl_->PrepareToDraw(frame);
+    if (draw_result == DRAW_ABORTED_CONTEXT_LOST) {
+      lost_output_surface = true;
+    } else {
       layer_tree_host_impl_->DrawLayers(frame, frame_begin_time);
       layer_tree_host_impl_->DidDrawAllLayers(*frame);
     }
-    lost_output_surface = layer_tree_host_impl_->IsContextLost();
 
     bool start_ready_animations = true;
     layer_tree_host_impl_->UpdateAnimationState(start_ready_animations);
@@ -447,7 +453,6 @@ bool SingleThreadProxy::DoComposite(base::TimeTicks frame_begin_time,
   }
 
   if (lost_output_surface) {
-    layer_tree_host_->DidLoseOutputSurface();
     return false;
   }