Cleanup namespace usage in public/platform/{Web[P-W]*,linux/*}.h

public/platform/WebRTCOfferOptions.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 WebRTCOfferOptions_h
 #define WebRTCOfferOptions_h
 
 #include "WebCommon.h"
 #include "WebNonCopyable.h"
 #include "WebPrivatePtr.h"
 
 namespace blink {
+
 class RTCOfferOptions;
-}
-
-namespace blink {
 
 class WebRTCOfferOptions {
 public:
     WebRTCOfferOptions() { }
     WebRTCOfferOptions(const WebRTCOfferOptions& other) { assign(other); }
     ~WebRTCOfferOptions() { reset(); }
 
     WebRTCOfferOptions& operator=(const WebRTCOfferOptions& other)
     {
         assign(other);
         return *this;
     }
 
     BLINK_PLATFORM_EXPORT void assign(const WebRTCOfferOptions&);
 
     BLINK_PLATFORM_EXPORT void reset();
     bool isNull() const { return m_private.isNull(); }
 
     BLINK_PLATFORM_EXPORT int32_t offerToReceiveVideo() const;
     BLINK_PLATFORM_EXPORT int32_t offerToReceiveAudio() const;
     BLINK_PLATFORM_EXPORT bool voiceActivityDetection() const;
     BLINK_PLATFORM_EXPORT bool iceRestart() const;
 
 #if INSIDE_BLINK
-    BLINK_PLATFORM_EXPORT WebRTCOfferOptions(const WTF::PassRefPtr<blink::RTCOfferOptions>&);
+    BLINK_PLATFORM_EXPORT WebRTCOfferOptions(const WTF::PassRefPtr<RTCOfferOptions>&);
 #endif
 
 private:
-    WebPrivatePtr<blink::RTCOfferOptions> m_private;
+    WebPrivatePtr<RTCOfferOptions> m_private;
 };
 
 } // namespace blink
 
 #endif // WebRTCOfferOptions_h