Clean up remaining uses of WebCore namespace

Source/core/dom/DOMRect.h

Index: Source/core/dom/DOMRect.h
diff --git a/Source/core/dom/DOMRect.h b/Source/core/dom/DOMRect.h
index af52d20395df9f594c3cb811bd68dd0e3c6e4b66..1f99d467698dfdbacc1ec19d3d4cbc7ed8d680cb 100644
--- a/Source/core/dom/DOMRect.h
+++ b/Source/core/dom/DOMRect.h
@@ -8,7 +8,7 @@
 #include "bindings/core/v8/Dictionary.h"
 #include "core/dom/DOMRectReadOnly.h"
 
-namespace WebCore {
+namespace blink {
 
 class DOMRect FINAL : public DOMRectReadOnly {
 public:
@@ -23,6 +23,6 @@ protected:
     DOMRect(double x, double y, double z, double w);
 };
 
-} // namespace WebCore
+} // namespace blink
 
 #endif