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

public/platform/WebSerializedOrigin.h

Index: public/platform/WebSerializedOrigin.h
diff --git a/public/platform/WebSerializedOrigin.h b/public/platform/WebSerializedOrigin.h
index 322ed82c903b9ba80cb23e8157a7b287b0721ba6..b79e65f5916c0ea249a640e99e96d5a7a66d4657 100644
--- a/public/platform/WebSerializedOrigin.h
+++ b/public/platform/WebSerializedOrigin.h
@@ -7,20 +7,20 @@
 
 #include "WebString.h"
 
-#if INSIDE_BLINK
-namespace blink { class SecurityOrigin; }
-#else
+#if !INSIDE_BLINK
 #include <url/origin.h>
 #endif
 
 namespace blink {
 
+class SecurityOrigin;
+
 // WebSerializedOrigin represents a serialized Web Origin specified in RFC6454.
 class WebSerializedOrigin {
 public:
     WebSerializedOrigin() : m_string("null") { }
 #if INSIDE_BLINK
-    BLINK_PLATFORM_EXPORT WebSerializedOrigin(const blink::SecurityOrigin&);
+    BLINK_PLATFORM_EXPORT WebSerializedOrigin(const SecurityOrigin&);
 #else
     WebSerializedOrigin(const url::Origin& origin) : m_string(WebString::fromUTF8(origin.string())) { }
     operator url::Origin() const { return url::Origin(m_string.utf8()); }