Clean up remaining uses of WebCore namespace

Source/modules/serviceworkers/CacheStorage.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 CacheStorage_h
 #define CacheStorage_h
 
 #include "bindings/core/v8/ScriptPromise.h"
 #include "bindings/core/v8/ScriptState.h"
 #include "bindings/core/v8/ScriptWrappable.h"
 #include "wtf/Forward.h"
 #include "wtf/Noncopyable.h"
 #include "wtf/RefCounted.h"
 
-namespace WebCore {
+namespace blink {
 
 // See https://slightlyoff.github.io/ServiceWorker/spec/service_worker/index.html#cache-storage
 
 class CacheStorage FINAL : public RefCountedWillBeGarbageCollected<CacheStorage>, public ScriptWrappable {
     WTF_MAKE_NONCOPYABLE(CacheStorage);
 public:
     static PassRefPtrWillBeRawPtr<CacheStorage> create();
 
     ScriptPromise createFunction(ScriptState*, const String& key);
     ScriptPromise rename(ScriptState*, const String& oldKey, const String& newKey);
     ScriptPromise get(ScriptState*, const String& key);
     ScriptPromise deleteFunction(ScriptState*, const String& key);
     ScriptPromise keys(ScriptState*);
 
     void trace(Visitor*) { }
 
 private:
     CacheStorage();
 };
 
-} // namespace WebCore
+} // namespace blink
 
 #endif // CacheStorage_h