aura: Support releasing the OutputSurface()

ui/compositor/compositor_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 "base/run_loop.h"
 #include "base/thread_task_runner_handle.h"
 #include "cc/output/begin_frame_args.h"
 #include "cc/test/begin_frame_args_test.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "ui/compositor/compositor.h"
+#include "ui/compositor/layer.h"
 #include "ui/compositor/test/context_factories_for_test.h"
+#include "ui/compositor/test/draw_waiter_for_test.h"
 
 using testing::Mock;
 using testing::_;
 
 namespace ui {
 namespace {
 
 class MockCompositorBeginFrameObserver : public CompositorBeginFrameObserver {
  public:
   MOCK_METHOD1(OnSendBeginFrame, void(const cc::BeginFrameArgs&));
@@ skipping 95 matching lines @@
   // So, it is not used for newly added observer.
   EXPECT_CALL(test_observer2, OnSendBeginFrame(_)).Times(0);
   compositor()->RemoveBeginFrameObserver(&test_observer);
   compositor()->RemoveBeginFrameObserver(&test_observer2);
   compositor()->AddBeginFrameObserver(&test_observer2);
   Mock::VerifyAndClearExpectations(&test_observer2);
 
   compositor()->RemoveBeginFrameObserver(&test_observer2);
 }
 
+TEST_F(CompositorTest, ReleaseWidgetWithOutputSurfaceNeverCreated) {
+  compositor()->SetVisible(false);
+  EXPECT_EQ(gfx::kNullAcceleratedWidget,
+            compositor()->ReleaseAcceleratedWidget());
+  compositor()->SetAcceleratedWidget(gfx::kNullAcceleratedWidget);
+  compositor()->SetVisible(true);
+}
+
+TEST_F(CompositorTest, CreateAndReleaseOutputSurface) {
+  scoped_ptr<Layer> root_layer(new Layer(ui::LAYER_SOLID_COLOR));
+  root_layer->SetBounds(gfx::Rect(10, 10));
+  compositor()->SetRootLayer(root_layer.get());
+  compositor()->SetScaleAndSize(1.0f, gfx::Size(10, 10));
+  DCHECK(compositor()->IsVisible());
+  compositor()->ScheduleDraw();
+  DrawWaiterForTest::WaitForCompositingEnded(compositor());
+  compositor()->SetVisible(false);
+  EXPECT_EQ(gfx::kNullAcceleratedWidget,

[danakj, 2015/10/06 18:28:12]

might be worth a test that verifies it gets back the right widget for non-null
case? maybe not, pretty simple

[no sievers, 2015/10/06 23:46:27]

But it goes into the non-offscreen creation path then, so I'd actually have to
pass a valid view surface handle here.

[danakj, 2015/10/07 20:44:42]

I was thinking of
https://code.google.com/p/chromium/codesearch#chromium/src/ui/compositor/laye...
these tests, not sure that would work here, but might. I don't see where we give
a widget to the compositor there, but they do draw to a xwindow..

+            compositor()->ReleaseAcceleratedWidget());
+  compositor()->SetAcceleratedWidget(gfx::kNullAcceleratedWidget);
+  compositor()->SetVisible(true);
+  compositor()->ScheduleDraw();
+  DrawWaiterForTest::WaitForCompositingEnded(compositor());
+  compositor()->SetRootLayer(nullptr);
+}
+
 }  // namespace ui