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

third_party/WebKit/Source/web/CompositorProxyClientImpl.cpp

+// 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 "web/CompositorProxyClientImpl.h"
+
+#include "core/dom/CompositorProxy.h"
+#include "modules/compositorworker/CompositorWorkerGlobalScope.h"
+#include "platform/TraceEvent.h"
+#include "web/CompositorMutatorImpl.h"
+
+namespace blink {
+
+CompositorProxyClientImpl::CompositorProxyClientImpl(CompositorMutatorImpl* mutator)
+    : m_mutator(mutator)
+    , m_globalScope(nullptr)
+    , m_executingAnimationFrameCallbacks(false)
+{
+}
+
+CompositorProxyClientImpl::~CompositorProxyClientImpl()
+{
+}
+
+DEFINE_TRACE(CompositorProxyClientImpl)
+{
+    visitor->trace(m_globalScope);
+    CompositorProxyClient::trace(visitor);
+}
+
+void CompositorProxyClientImpl::setGlobalScope(WorkerGlobalScope* scope)
+{
+    TRACE_EVENT0("compositor-worker", "CompositorProxyClientImpl::setGlobalScope");
+    m_globalScope = static_cast<CompositorWorkerGlobalScope*>(scope);
+    if (m_globalScope)
+        m_mutator->registerClient(this);
+    else
+        m_mutator->unregisterClient(this);
+}
+
+void CompositorProxyClientImpl::requestMutation()
+{
+    TRACE_EVENT0("compositor-worker", "CompositorProxyClientImpl::requestMutation");
+    m_requestedAnimationFrameCallbacks = true;
+    m_mutator->setNeedsMutate();
+}
+
+bool CompositorProxyClientImpl::mutate(double timeNow)
+{
+    if (!m_globalScope)
+        return false;
+
+    TRACE_EVENT0("compositor-worker", "CompositorProxyClientImpl::mutate");
+    if (!m_requestedAnimationFrameCallbacks)
+        return false;
+
+    m_requestedAnimationFrameCallbacks = false;
+    {
+        TemporaryChange<bool> temporary(m_executingAnimationFrameCallbacks, true);

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

What's the point of changing this? It's never read. CompositorWorkerGlobalScope
has a similar one that is used, but does CompositorProxyClientImpl care at all?

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

I believe it does care in a subsequent patch but I'll remove this until we need
it.

+        m_requestedAnimationFrameCallbacks = executeAnimationFrameCallbacks(timeNow);
+    }
+
+    return m_requestedAnimationFrameCallbacks;
+}
+
+bool CompositorProxyClientImpl::executeAnimationFrameCallbacks(double time)
+{
+    TRACE_EVENT0("compositor-worker", "CompositorProxyClientImpl::executeAnimationFrameCallbacks");
+    const bool shouldReinvoke = m_globalScope->executeAnimationFrameCallbacks(time);
+    return shouldReinvoke;
+}
+
+} // namespace blink