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

third_party/WebKit/Source/core/dom/CompositorProxyClient.h

Index: third_party/WebKit/Source/core/dom/CompositorProxyClient.h
diff --git a/third_party/WebKit/Source/core/dom/CompositorProxyClient.h b/third_party/WebKit/Source/core/dom/CompositorProxyClient.h
new file mode 100644
index 0000000000000000000000000000000000000000..2bb59808f6a046db3779a2d10314b9556e58b089
--- /dev/null
+++ b/third_party/WebKit/Source/core/dom/CompositorProxyClient.h
@@ -0,0 +1,46 @@
+// 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.
+
+#ifndef CompositorProxyClient_h
+#define CompositorProxyClient_h
+
+#include "bindings/core/v8/ScopedPersistent.h"
+#include "core/CoreExport.h"
+#include "core/workers/WorkerClients.h"
+#include "platform/heap/Handle.h"
+#include "wtf/Noncopyable.h"
+
+#include <v8.h>
+
+namespace blink {
+
+class CompositorProxy;
+class Event;
+class ScriptState;
+class WorkerClients;
+class WorkerGlobalScope;
+
+class CORE_EXPORT CompositorProxyClient : public GarbageCollectedFinalized<CompositorProxyClient>, public Supplement<WorkerClients> {

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

Can this just be GarbageCollected<CompositorProxyClient>? I don't see the
destructor of it or its subclass doing anything interesting.

[flackr, 2016/04/25 14:06:27]

Yes, it totally can, done. In a future patch the destructor of
CompositorProxyClientImpl will be doing interesting things. :-)

+    WTF_MAKE_NONCOPYABLE(CompositorProxyClient);
+    USING_GARBAGE_COLLECTED_MIXIN(CompositorProxyClient);
+
+public:
+    CompositorProxyClient() {}
+    virtual ~CompositorProxyClient() {}
+    DEFINE_INLINE_VIRTUAL_TRACE() {}
+
+    static CompositorProxyClient* from(WorkerClients*);
+    static const char* supplementName();
+
+    virtual bool mutate(double time) = 0;

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

Here too, please explain what time is.

[jbroman, 2016/04/20 21:06:42]

Does this method need to be virtual? Does anyone call it who can't just as
easily call it on the subclass?

[flackr, 2016/04/25 14:06:27]

I've changed this here and elsewhere to be monotonicTime, monotonicTimeNow and
highResTimeMs consistent with the requestAnimationFrame callback:
https://code.google.com/p/chromium/codesearch#chromium/src/third_party/WebKit...

+
+    virtual void setGlobalScope(WorkerGlobalScope*) = 0;
+    virtual void requestMutation() = 0;

[jbroman, 2016/04/20 21:06:42]

This name feels strange (the caller is the one that will actually be doing the
mutation), and if you look at the call stack, names go roughly
requestAnimationFrame -> requestMutation -> setNeedsMutate -> SetNeedsMutate.

WDYT about renaming this, to either requestAnimationFrame or setNeedsMutate?

[flackr, 2016/04/25 14:06:27]

I agree, I think calling it requestAnimationFrame makes the most sense.

+};
+
+CORE_EXPORT void provideCompositorProxyClientTo(WorkerClients*, CompositorProxyClient*);
+
+} // namespace blink
+
+#endif // CompositorProxyClient_h