compositor-worker: cc->blink mutation plumbing

third_party/WebKit/Source/web/WebViewImpl.cpp

Index: third_party/WebKit/Source/web/WebViewImpl.cpp
diff --git a/third_party/WebKit/Source/web/WebViewImpl.cpp b/third_party/WebKit/Source/web/WebViewImpl.cpp
index b5481838464c7a5f293401b00d00f0f4d9783db6..7cc19315d5af09f5980311b6285b52620207ef32 100644
--- a/third_party/WebKit/Source/web/WebViewImpl.cpp
+++ b/third_party/WebKit/Source/web/WebViewImpl.cpp
@@ -34,6 +34,7 @@
 #include "core/HTMLNames.h"
 #include "core/InputTypeNames.h"
 #include "core/clipboard/DataObject.h"
+#include "core/dom/DOMNodeIds.h"
 #include "core/dom/Document.h"
 #include "core/dom/Fullscreen.h"
 #include "core/dom/LayoutTreeBuilderTraversal.h"
@@ -111,6 +112,7 @@
 #include "platform/exported/WebActiveGestureAnimation.h"
 #include "platform/fonts/FontCache.h"
 #include "platform/graphics/Color.h"
+#include "platform/graphics/CompositorMutation.h"
 #include "platform/graphics/FirstPaintInvalidationTracking.h"
 #include "platform/graphics/GraphicsContext.h"
 #include "platform/graphics/Image.h"
@@ -4450,6 +4452,19 @@ void WebViewImpl::recordFrameTimingEvent(FrameTimingEventType eventType, int64_t
     }
 }
 
+void WebViewImpl::applyMutations(const WebCompositorMutations& mutations)
+{
+    TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("compositor-worker"), "WebViewImpl::applyMutations");
+    for (const auto& entry : static_cast<const CompositorMutations&>(mutations).map) {
+        int elementId = entry.key;
+        const CompositorMutation& mutation = *entry.value;
+        Node* node = DOMNodeIds::nodeForId(elementId);
+        if (!node || !toElement(node))

[jbroman, 2016/01/23 23:55:09]

toElement is not a check; it's a cast (with an assertion that's not run in
release).

You want "!node || !node->isElementNode()" if you actually want to check. If
you're confident this can only ever be an element, then the second part of the
check isn't necessary.

[majidvp, 2016/01/25 20:40:11]

It is guaranteed to be an an Element. Check removed.

+            continue;
+        toElement(node)->updateFromMutation(mutation);
+    }
+}
+
 void WebViewImpl::updateLayerTreeViewport()
 {
     if (!page() || !m_layerTreeView)