aura: Support releasing the OutputSurface()

ui/compositor/compositor_unittest.cc

Index: ui/compositor/compositor_unittest.cc
diff --git a/ui/compositor/compositor_unittest.cc b/ui/compositor/compositor_unittest.cc
index b182033dabdc861d64a7bfee61beceea1b315430..a53bdc2ab0f2b5d1095bde808917bb7947ca3c72 100644
--- a/ui/compositor/compositor_unittest.cc
+++ b/ui/compositor/compositor_unittest.cc
@@ -9,7 +9,9 @@
 #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::_;
@@ -125,4 +127,30 @@ TEST_F(CompositorTest, AddAndRemoveBeginFrameObserver) {
   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