Cleanup namespace usage in Source/core/platform/[A-Z]*.h

Source/platform/ContentDecryptionModuleResult.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef ContentDecryptionModuleResult_h
 #define ContentDecryptionModuleResult_h
 
 #include "platform/heap/Handle.h"
 #include "public/platform/WebContentDecryptionModuleException.h"
 #include "public/platform/WebContentDecryptionModuleResult.h"
 
 namespace blink {
+
 class WebString;
-}
-
-namespace blink {
 
 // Used to notify completion of a CDM operation.
 class ContentDecryptionModuleResult : public GarbageCollectedFinalized<ContentDecryptionModuleResult> {
 public:
     virtual ~ContentDecryptionModuleResult() { }
 
     virtual void complete() = 0;
-    virtual void completeWithSession(blink::WebContentDecryptionModuleResult::SessionStatus) = 0;
-    virtual void completeWithError(blink::WebContentDecryptionModuleException, unsigned long systemCode, const blink::WebString&) = 0;
+    virtual void completeWithSession(WebContentDecryptionModuleResult::SessionStatus) = 0;
+    virtual void completeWithError(WebContentDecryptionModuleException, unsigned long systemCode, const WebString&) = 0;
 
-    blink::WebContentDecryptionModuleResult result()
+    WebContentDecryptionModuleResult result()
     {
-        return blink::WebContentDecryptionModuleResult(this);
+        return WebContentDecryptionModuleResult(this);
     }
 
     virtual void trace(Visitor*) { }
 };
 
 } // namespace blink
 
 #endif // ContentDecryptionModuleResult_h