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

third_party/WebKit/Source/platform/graphics/CompositorMutator.h

Index: third_party/WebKit/Source/platform/graphics/CompositorMutator.h
diff --git a/third_party/WebKit/Source/platform/graphics/CompositorMutator.h b/third_party/WebKit/Source/platform/graphics/CompositorMutator.h
new file mode 100644
index 0000000000000000000000000000000000000000..2fffa6180cfb976401ab1f455e37e2dc7b8a0bce
--- /dev/null
+++ b/third_party/WebKit/Source/platform/graphics/CompositorMutator.h
@@ -0,0 +1,22 @@
+// Copyright 2016 The Chromium Authors. All rights reserved.

[jbroman, 2016/04/20 19:24:51]

this file should be added to blink_platform.gypi

[flackr, 2016/04/25 14:06:28]

Done.

+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CompositorMutator_h
+#define CompositorMutator_h
+
+#include "wtf/RefCounted.h"
+
+namespace blink {
+
+class CompositorMutator {
+public:
+    virtual ~CompositorMutator() {}
+
+    // Called from compositor thread which does not participate in GC cycle

[jbroman, 2016/04/20 19:24:51]

Could you elaborate on the meaning of this comment? I'm not sure what "does not
participate in GC cycle" has to do with this method. Does it mean overrides
shouldn't use Oilpan?

+    virtual bool mutate(double timeNow) = 0;

[jbroman, 2016/04/20 19:24:51]

What is timeNow (time-ticks or real time, seconds or millis, etc)?

[flackr, 2016/04/25 14:06:28]

Done, I think. Let me know if you think it needs further clarification from
monotonicTimeNow.

+};
+
+} // namespace blink
+
+#endif // CompositorMutator_h