cc: Defer first OutputSurface creation until client is ready

cc/trees/layer_tree_host_unittest_context.cc

 // Copyright 2012 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.h"
 
 #include "base/basictypes.h"
 #include "cc/layers/content_layer.h"
 #include "cc/layers/delegated_frame_provider.h"
 #include "cc/layers/delegated_frame_resource_collection.h"
@@ skipping 1268 matching lines @@
     if (host_impl->active_tree()->source_frame_number() == 2) {
       // Lose the context during draw on the second commit. This will cause
       // a third commit to recover.
       context3d_->set_times_bind_texture_succeeds(0);
     }
     return true;
   }
 
   virtual scoped_ptr<OutputSurface> CreateOutputSurface(
       bool fallback) OVERRIDE {
-    if (layer_tree_host()) {
+    if (layer_tree_host()->source_frame_number() > 0) {

[danakj, 2013/11/26 16:35:15]

Can you explain this one?

[no sievers, 2013/11/26 19:28:37]

What this function was doing is return an output surface the first time (when
layer_tree_host() still returns NULL because the first_output_surface creation
is triggered from  LayerTreeHostForTesting::Create() itself), but fail the
output surface creation when we lose the context  (triggered from
PrepareToDrawOnThread() above).

Since the previous check did not work anymore after my change, I had to change
it, but it should have the same effect.

[no sievers, 2013/11/26 19:30:23]

Actually, it's not failing the output surface creation the second time. It's
just verifying the assumption here.
I'll add a comment too.

[danakj, 2013/11/26 19:44:58]

Ah, right ok. Comment would be nice thanks :)

       lost_context_ = true;
       EXPECT_EQ(layer_tree_host()->source_frame_number(), 3);
     }
     return LayerTreeHostContextTest::CreateOutputSurface(fallback);
   }
 
   virtual void DidCommitAndDrawFrame() OVERRIDE {
     ASSERT_TRUE(layer_tree_host()->hud_layer());
     // End the test once we know the 3nd frame drew.
     if (layer_tree_host()->source_frame_number() < 4) {
@@ skipping 455 matching lines @@
     EndTest();
   }
 
  private:
   int failure_count_;
 };
 
 SINGLE_AND_MULTI_THREAD_TEST_F(
     LayerTreeHostContextTestFailsToCreateSurface);
 
-// Not reusing LayerTreeTest because it expects creating LTH to always succeed.
-class LayerTreeHostTestCannotCreateIfCannotCreateOutputSurface
-    : public testing::Test,
-      public FakeLayerTreeHostClient {
- public:
-  LayerTreeHostTestCannotCreateIfCannotCreateOutputSurface()
-      : FakeLayerTreeHostClient(FakeLayerTreeHostClient::DIRECT_3D) {}
-
-  // FakeLayerTreeHostClient implementation.
-  virtual scoped_ptr<OutputSurface> CreateOutputSurface(bool fallback)
-      OVERRIDE {
-    return scoped_ptr<OutputSurface>();
-  }
-
-  void RunTest(bool threaded,
-               bool delegating_renderer,
-               bool impl_side_painting) {
-    LayerTreeSettings settings;
-    settings.impl_side_painting = impl_side_painting;
-    if (threaded) {
-      scoped_ptr<base::Thread> impl_thread(new base::Thread("LayerTreeTest"));
-      ASSERT_TRUE(impl_thread->Start());
-      ASSERT_TRUE(impl_thread->message_loop_proxy().get());
-      scoped_ptr<LayerTreeHost> layer_tree_host = LayerTreeHost::CreateThreaded(
-          this, NULL, settings, impl_thread->message_loop_proxy());
-      EXPECT_FALSE(layer_tree_host);
-    } else {
-      scoped_ptr<LayerTreeHost> layer_tree_host =
-          LayerTreeHost::CreateSingleThreaded(this, this, NULL, settings);
-      EXPECT_FALSE(layer_tree_host);
-    }
-  }
-};
-
-SINGLE_AND_MULTI_THREAD_TEST_F(
-    LayerTreeHostTestCannotCreateIfCannotCreateOutputSurface);
-
 class UIResourceLostTest : public LayerTreeHostContextTest {
  public:
   UIResourceLostTest() : time_step_(0) {}
   virtual void InitializeSettings(LayerTreeSettings* settings) OVERRIDE {
     settings->texture_id_allocation_chunk_size = 1;
   }
   virtual void BeginTest() OVERRIDE { PostSetNeedsCommitToMainThread(); }
   virtual void AfterTest() OVERRIDE {}
 
   // This is called on the main thread after each commit and
@@ skipping 478 matching lines @@
  protected:
   FakeContentLayerClient client_;
   scoped_refptr<FakeContentLayer> layer_;
   int num_commits_;
 };
 
 SINGLE_AND_MULTI_THREAD_TEST_F(LayerTreeHostContextTestSurfaceCreateCallback);
 
 }  // namespace
 }  // namespace cc