cc: Switch to Chromium DCHECKs and LOGs

cc/tree_synchronizer.cc

Index: cc/tree_synchronizer.cc
diff --git a/cc/tree_synchronizer.cc b/cc/tree_synchronizer.cc
index b7e76bbe9ab16d6843bfb26937329c17e35b6233..d14def49f461193150135775555866a26352e8a0 100644
--- a/cc/tree_synchronizer.cc
+++ b/cc/tree_synchronizer.cc
@@ -100,8 +100,8 @@ void TreeSynchronizer::updateScrollbarLayerPointersRecursive(const RawPtrCCLayer
     iter = newLayers.find(scrollbarLayer->scrollLayerId());
     CCLayerImpl* ccScrollLayerImpl = iter != newLayers.end() ? iter->second : NULL;
 
-    ASSERT(ccScrollbarLayerImpl);
-    ASSERT(ccScrollLayerImpl);
+    CC_DCHECK(ccScrollbarLayerImpl);
+    CC_DCHECK(ccScrollLayerImpl);
 
     if (ccScrollbarLayerImpl->orientation() == WebKit::WebScrollbar::Horizontal)
         ccScrollLayerImpl->setHorizontalScrollbarLayer(ccScrollbarLayerImpl);