LayerTreeHostImpl knows if it has an output surface.

cc/trees/layer_tree_host_impl_unittest.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/layer_tree_host_impl.h"
 
 #include <cmath>
 
 #include "base/bind.h"
 #include "base/command_line.h"
@@ skipping 6797 matching lines @@
 
   EXPECT_EQ(2u, raw_pending_layer->did_become_active_call_count());
   EXPECT_EQ(1u, raw_mask_layer->did_become_active_call_count());
   EXPECT_EQ(0u, raw_replica_mask_layer->did_become_active_call_count());
   pending_tree->DidBecomeActive();
   EXPECT_EQ(3u, raw_pending_layer->did_become_active_call_count());
   EXPECT_EQ(2u, raw_mask_layer->did_become_active_call_count());
   EXPECT_EQ(1u, raw_replica_mask_layer->did_become_active_call_count());
 }
 
+class LayerTreeHostImplCountingLostSurfaces : public LayerTreeHostImplTest {
+ public:
+  LayerTreeHostImplCountingLostSurfaces() : num_lost_surfaces_(0) {}
+  virtual void DidLoseOutputSurfaceOnImplThread() OVERRIDE {
+    num_lost_surfaces_++;
+  }
+
+ protected:
+  int num_lost_surfaces_;
+};
+
+TEST_F(LayerTreeHostImplCountingLostSurfaces, TwiceLostSurface) {
+  EXPECT_EQ(0, num_lost_surfaces_);
+  EXPECT_FALSE(host_impl_->IsContextLost());
+  host_impl_->DidLoseOutputSurface();
+  EXPECT_TRUE(host_impl_->IsContextLost());
+  EXPECT_EQ(1, num_lost_surfaces_);
+  host_impl_->DidLoseOutputSurface();
+  EXPECT_TRUE(host_impl_->IsContextLost());
+  EXPECT_EQ(1, num_lost_surfaces_);
+}
+
+TEST_F(LayerTreeHostImplCountingLostSurfaces, TwiceInitializeRenderer) {
+  // We should be able to tolerate a re-initialization of the

[danakj, 2014/08/06 18:56:44]

I don't think this is true. It should never happen because we never go about
requesting a new outputsurface/renderer until we see the callback now.

[dneto, 2014/08/06 20:20:35]

So should I remove this test and add the
DCHECK(!renderer_||!have_valid_output_surface_)
back into InitializeRenderer?

+  // renderer if an output surface has not been able to invoke
+  // our lost-surface callback in time.
+  // See crbug.com/392891
+  EXPECT_EQ(0, num_lost_surfaces_);
+  host_impl_->InitializeRenderer(CreateOutputSurface());
+  EXPECT_EQ(0, num_lost_surfaces_);
+  host_impl_->InitializeRenderer(CreateOutputSurface());
+  EXPECT_EQ(0, num_lost_surfaces_);
+}
+
 }  // namespace
 }  // namespace cc