Cleanup namespace usage in Source/web/*.h

Source/web/PrerendererClientImpl.h

Index: Source/web/PrerendererClientImpl.h
diff --git a/Source/web/PrerendererClientImpl.h b/Source/web/PrerendererClientImpl.h
index 3fb09ffb67751648f22562fbbdd103d8a46f5aa4..d00d91f2c48c069f769d6df751defd3abf26e084 100644
--- a/Source/web/PrerendererClientImpl.h
+++ b/Source/web/PrerendererClientImpl.h
@@ -37,22 +37,19 @@
 #include "wtf/PassRefPtr.h"
 
 namespace blink {
-class Prerender;
-}
-
-namespace blink {
 
+class Prerender;
 class WebPrerendererClient;
 
-class PrerendererClientImpl FINAL : public NoBaseWillBeGarbageCollected<PrerendererClientImpl>, public blink::PrerendererClient {
+class PrerendererClientImpl FINAL : public NoBaseWillBeGarbageCollected<PrerendererClientImpl>, public PrerendererClient {
     WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(PrerendererClientImpl);
     WTF_MAKE_NONCOPYABLE(PrerendererClientImpl);
 public:
     explicit PrerendererClientImpl(WebPrerendererClient*);
 
-    void willAddPrerender(blink::Prerender*) OVERRIDE;
+    void willAddPrerender(Prerender*) OVERRIDE;
 
-    virtual void trace(blink::Visitor* visitor) OVERRIDE { blink::PrerendererClient::trace(visitor); }
+    virtual void trace(Visitor* visitor) OVERRIDE { PrerendererClient::trace(visitor); }
 
 private:
     WebPrerendererClient* m_client;