[compositorworker] compositor proxy mutation updates underlying layers

third_party/WebKit/Source/web/CompositorProxyClientImpl.cpp

Index: third_party/WebKit/Source/web/CompositorProxyClientImpl.cpp
diff --git a/third_party/WebKit/Source/web/CompositorProxyClientImpl.cpp b/third_party/WebKit/Source/web/CompositorProxyClientImpl.cpp
index f477ca2bcabce6c21fc276dd52f500bc44077150..4a621c5f1ab5d7c8d7e5e260394e8bf827287093 100644
--- a/third_party/WebKit/Source/web/CompositorProxyClientImpl.cpp
+++ b/third_party/WebKit/Source/web/CompositorProxyClientImpl.cpp
@@ -7,11 +7,35 @@
 #include "core/dom/CompositorProxy.h"
 #include "modules/compositorworker/CompositorWorkerGlobalScope.h"
 #include "platform/TraceEvent.h"
+#include "platform/graphics/CompositorMutableStateProvider.h"
 #include "web/CompositorMutatorImpl.h"
 #include "wtf/CurrentTime.h"
 
 namespace blink {
 
+// A helper class that updates proxies mutable state on creation and reset it
+// on destruction. This can be used with rAF callback to ensure no mutation is
+// allowed outside rAF.
+class ScopedCompositorMutableState final {
+    WTF_MAKE_NONCOPYABLE(ScopedCompositorMutableState);
+    STACK_ALLOCATED();
+public:
+    ScopedCompositorMutableState(HeapHashSet<WeakMember<CompositorProxy>>& proxies, CompositorMutableStateProvider* stateProvider)
+        : m_proxies(proxies)
+    {
+        for (CompositorProxy* proxy : m_proxies)
+            proxy->takeCompositorMutableState(stateProvider->getMutableStateFor(proxy->elementId()));
+
+    }
+    ~ScopedCompositorMutableState()
+    {
+        for (CompositorProxy* proxy : m_proxies)
+            proxy->takeCompositorMutableState(nullptr);
+    }
+private:
+    HeapHashSet<WeakMember<CompositorProxy>>& m_proxies;
+};
+
 CompositorProxyClientImpl::CompositorProxyClientImpl(CompositorMutatorImpl* mutator)
     : m_mutator(mutator)
     , m_globalScope(nullptr)
@@ -42,7 +66,7 @@ void CompositorProxyClientImpl::requestAnimationFrame()
     m_mutator->setNeedsMutate();
 }
 
-bool CompositorProxyClientImpl::mutate(double monotonicTimeNow)
+bool CompositorProxyClientImpl::mutate(double monotonicTimeNow, CompositorMutableStateProvider* stateProvider)
 {
     if (!m_globalScope)
         return false;
@@ -51,7 +75,10 @@ bool CompositorProxyClientImpl::mutate(double monotonicTimeNow)
     if (!m_requestedAnimationFrameCallbacks)
         return false;
 
-    m_requestedAnimationFrameCallbacks = executeAnimationFrameCallbacks(monotonicTimeNow);
+    {
+        ScopedCompositorMutableState mutableState(m_proxies, stateProvider);
+        m_requestedAnimationFrameCallbacks = executeAnimationFrameCallbacks(monotonicTimeNow);
+    }
 
     return m_requestedAnimationFrameCallbacks;
 }
@@ -59,10 +86,10 @@ bool CompositorProxyClientImpl::mutate(double monotonicTimeNow)
 bool CompositorProxyClientImpl::executeAnimationFrameCallbacks(double monotonicTimeNow)
 {
     TRACE_EVENT0("compositor-worker", "CompositorProxyClientImpl::executeAnimationFrameCallbacks");
+
     // Convert to zero based document time in milliseconds consistent with requestAnimationFrame.
     double highResTimeMs = 1000.0 * (monotonicTimeNow - m_globalScope->timeOrigin());
-    const bool shouldReinvoke = m_globalScope->executeAnimationFrameCallbacks(highResTimeMs);
-    return shouldReinvoke;
+    return m_globalScope->executeAnimationFrameCallbacks(highResTimeMs);
 }
 
 void CompositorProxyClientImpl::registerCompositorProxy(CompositorProxy* proxy)