Cleanup namespace usage in public/web/Web[N-Z]*.h.

public/web/WebPerformance.h

Index: public/web/WebPerformance.h
diff --git a/public/web/WebPerformance.h b/public/web/WebPerformance.h
index 48d17123188af1d23a34c545e283abac5e4a217d..6fd8c5bf5413050d4719f64174353cc691abf1b3 100644
--- a/public/web/WebPerformance.h
+++ b/public/web/WebPerformance.h
@@ -39,10 +39,10 @@
 #include "platform/heap/Handle.h"
 #endif
 
-namespace blink { class Performance; }
-
 namespace blink {
 
+class Performance;
+
 class WebPerformance {
 public:
     ~WebPerformance() { reset(); }
@@ -86,12 +86,12 @@ public:
     BLINK_EXPORT double loadEventEnd() const;
 
 #if BLINK_IMPLEMENTATION
-    WebPerformance(const PassRefPtrWillBeRawPtr<blink::Performance>&);
-    WebPerformance& operator=(const PassRefPtrWillBeRawPtr<blink::Performance>&);
+    WebPerformance(const PassRefPtrWillBeRawPtr<Performance>&);
+    WebPerformance& operator=(const PassRefPtrWillBeRawPtr<Performance>&);
 #endif
 
 private:
-    WebPrivatePtr<blink::Performance> m_private;
+    WebPrivatePtr<Performance> m_private;
 };
 
 } // namespace blink