compositor-worker: Initialize CW machinery plumbing to compositor and fire CW rAF callbacks.

third_party/WebKit/Source/platform/graphics/CompositorMutatorClientTest.cpp

 // Copyright 2016 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 "platform/graphics/CompositorMutatorClient.h"
 
 #include "base/callback.h"
 #include "platform/graphics/CompositorMutation.h"
 #include "platform/graphics/CompositorMutationsTarget.h"
+#include "platform/graphics/CompositorMutator.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "wtf/OwnPtr.h"
 
 using ::testing::_;
 
 namespace blink {
 namespace {
 
+class MockCompositorMutator : public GarbageCollected<MockCompositorMutator>, public CompositorMutator {

[jbroman, 2016/05/04 22:11:06]

super-nit: consider not using the term "Mock" when the object doesn't have
expectations (suggest "NullCompositorMutator",  "DummyCompositorMutator" or
perhaps "StubCompositorMutator").
(http://martinfowler.com/articles/mocksArentStubs.html via danakj)

We unfortunately aren't consistent about this, though. :(

[flackr, 2016/05/05 14:04:15]

Done.

+    USING_GARBAGE_COLLECTED_MIXIN(MockCompositorMutator);
+public:
+    MockCompositorMutator() {}
+
+    bool mutate(double monotonicTimeNow) override { return false; }
+};
+
 class MockCompositoMutationsTarget : public CompositorMutationsTarget {
 public:
     MOCK_METHOD1(applyMutations, void(CompositorMutations*));
 };
 
 TEST(CompositorMutatorClient, CallbackForNonNullMutationsShouldApply)
 {
     MockCompositoMutationsTarget target;
 
-    CompositorMutatorClient client(&target);
+    CompositorMutatorClient client(new MockCompositorMutator, &target);
     OwnPtr<CompositorMutations> mutations = adoptPtr(new CompositorMutations());
     client.setMutationsForTesting(mutations.release());
 
     EXPECT_CALL(target, applyMutations(_));
     client.TakeMutations().Run();
 }
 
 TEST(CompositorMutatorClient, CallbackForNullMutationsShouldBeNoop)
 {
     MockCompositoMutationsTarget target;
-    CompositorMutatorClient client(&target);
+    CompositorMutatorClient client(new MockCompositorMutator, &target);
 
     EXPECT_CALL(target, applyMutations(_)).Times(0);
     EXPECT_TRUE(client.TakeMutations().is_null());
 }
 
 } // namespace
 } // namespace blink