WIP - compositor worker mega patch.

cc/blink/web_compositor_mutable_state_provider_impl.cc

Index: cc/blink/web_compositor_mutable_state_provider_impl.cc
diff --git a/cc/blink/web_compositor_mutable_state_provider_impl.cc b/cc/blink/web_compositor_mutable_state_provider_impl.cc
new file mode 100644
index 0000000000000000000000000000000000000000..c6e898db3cfd1cae5f9ff40e3592a3978cdafa0c
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+++ b/cc/blink/web_compositor_mutable_state_provider_impl.cc
@@ -0,0 +1,33 @@
+// 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 "cc/blink/web_compositor_mutable_state_provider_impl.h"
+
+#include "cc/animation/layer_tree_mutation.h"
+#include "cc/blink/web_compositor_mutable_state_impl.h"
+#include "cc/layers/layer_impl.h"
+#include "cc/trees/layer_tree_impl.h"
+
+namespace cc_blink {
+
+WebCompositorMutableStateProviderImpl::WebCompositorMutableStateProviderImpl(
+    cc::LayerTreeImpl* state,
+    cc::LayerTreeMutationMap* mutations)
+    : state_(state), mutations_(mutations) {}
+
+WebCompositorMutableStateProviderImpl::
+    ~WebCompositorMutableStateProviderImpl() {}
+
+blink::WebCompositorMutableState*
+WebCompositorMutableStateProviderImpl::getCompositorMutableStateFor(
+    uint64_t element_id) {
+  cc::LayerTreeImpl::ElementLayers layers;
+  if (!state_->GetMutableLayers(element_id, &layers))
+    return nullptr;
+
+  return new WebCompositorMutableStateImpl(&(*mutations_)[element_id],
+                                           layers.main, layers.scroll);
+}
+
+}  // namespace cc_blink