exo: Handle lost context situations properly.

components/exo/surface_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/bind.h"
 #include "components/exo/buffer.h"
 #include "components/exo/surface.h"
 #include "components/exo/test/exo_test_base.h"
 #include "components/exo/test/exo_test_helper.h"
 #include "testing/gtest/include/gtest/gtest.h"
@@ skipping 14 matching lines @@
   gfx::Size buffer_size(256, 256);
   scoped_ptr<Buffer> buffer(
       new Buffer(exo_test_helper()->CreateGpuMemoryBuffer(buffer_size).Pass(),
                  GL_TEXTURE_2D));
 
   // Set the release callback that will be run when buffer is no longer in use.
   int release_buffer_call_count = 0;
   buffer->set_release_callback(
       base::Bind(&ReleaseBuffer, base::Unretained(&release_buffer_call_count)));
 
-  scoped_ptr<Surface> surface1(new Surface);
-  scoped_ptr<Surface> surface2(new Surface);
+  scoped_ptr<Surface> surface(new Surface);
 
   // Attach the buffer to surface1.
-  surface1->Attach(buffer.get());
-  surface1->Commit();
+  surface->Attach(buffer.get());
+  surface->Commit();
 
-  // Attaching buffer to surface2 when it is already attached to surface1
-  // should fail and buffer should remain attached to surface1.
-  surface2->Attach(buffer.get());
-  surface2->Commit();
+  // Commit without calling Attach() should have no effect.
+  surface->Commit();
+  EXPECT_EQ(0, release_buffer_call_count);
 
-  // Attach a null buffer to surface1, this should release the previously
+  // Attach a null buffer to surface, this should release the previously
   // attached buffer.
-  surface1->Attach(nullptr);
-  surface1->Commit();
-  ASSERT_EQ(release_buffer_call_count, 1);
+  surface->Attach(nullptr);
+  surface->Commit();
+  ASSERT_EQ(1, release_buffer_call_count);
 }
 
 TEST_F(SurfaceTest, Damage) {
   gfx::Size buffer_size(256, 256);
   scoped_ptr<Buffer> buffer(
       new Buffer(exo_test_helper()->CreateGpuMemoryBuffer(buffer_size).Pass(),
                  GL_TEXTURE_2D));
   scoped_ptr<Surface> surface(new Surface);
 
   // Attach the buffer to the surface. This will update the pending bounds of
@@ skipping 34 matching lines @@
 
 TEST_F(SurfaceTest, Commit) {
   scoped_ptr<Surface> surface(new Surface);
 
   // Calling commit without a buffer should succeed.
   surface->Commit();
 }
 
 }  // namespace
 }  // namespace exo