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

Source/platform/HostWindow.h

Index: Source/platform/HostWindow.h
diff --git a/Source/platform/HostWindow.h b/Source/platform/HostWindow.h
index c1a0be62fb6b59a3ba315422f256d6c4647f2ee4..5744f972cd22e9817af0bd11713048e5b6fcd8c7 100644
--- a/Source/platform/HostWindow.h
+++ b/Source/platform/HostWindow.h
@@ -31,14 +31,11 @@
 #include "wtf/Noncopyable.h"
 
 namespace blink {
-struct WebScreenInfo;
-}
-
-namespace blink {
 class Cursor;
 class IntPoint;
 class IntRect;
 class IntSize;
+struct WebScreenInfo;
 
 class PLATFORM_EXPORT HostWindow {
     WTF_MAKE_NONCOPYABLE(HostWindow); WTF_MAKE_FAST_ALLOCATED;
@@ -57,7 +54,7 @@ public:
     // Methods for doing coordinate conversions to screen coordinates.
     virtual IntRect rootViewToScreen(const IntRect&) const = 0;
 
-    virtual blink::WebScreenInfo screenInfo() const = 0;
+    virtual WebScreenInfo screenInfo() const = 0;
 
     virtual void scheduleAnimation() = 0;
 };