Cleanup namespace usage in Source/web/*.h

Source/web/MediaKeysClientImpl.h

Index: Source/web/MediaKeysClientImpl.h
diff --git a/Source/web/MediaKeysClientImpl.h b/Source/web/MediaKeysClientImpl.h
index 1ff7fc354c21b3fe0e410f5f52ba3f8dd70e86e0..cc6510b6878120fbd9f82d9c5d4ec95bb49a4a63 100644
--- a/Source/web/MediaKeysClientImpl.h
+++ b/Source/web/MediaKeysClientImpl.h
@@ -13,12 +13,12 @@ namespace blink {
 class WebContentDecryptionModule;
 class WebViewImpl;
 
-class MediaKeysClientImpl FINAL : public blink::MediaKeysClient {
+class MediaKeysClientImpl FINAL : public MediaKeysClient {
 public:
     MediaKeysClientImpl();
 
-    // blink::MediaKeysClient implementation.
-    virtual PassOwnPtr<WebContentDecryptionModule> createContentDecryptionModule(blink::ExecutionContext*, const String& keySystem) OVERRIDE;
+    // MediaKeysClient implementation.
+    virtual PassOwnPtr<WebContentDecryptionModule> createContentDecryptionModule(ExecutionContext*, const String& keySystem) OVERRIDE;
 };
 
 } // namespace blink