Cleanup namespace usage in public/web/Web[A-M]*.h.

public/web/WebDateTimeSuggestion.h

Index: public/web/WebDateTimeSuggestion.h
diff --git a/public/web/WebDateTimeSuggestion.h b/public/web/WebDateTimeSuggestion.h
index b62a38e23384340d7328e18154434ae16083165b..e2266b725a9db9be8bffa674e21d9d31890b5f03 100644
--- a/public/web/WebDateTimeSuggestion.h
+++ b/public/web/WebDateTimeSuggestion.h
@@ -28,12 +28,10 @@
 
 #include "public/platform/WebString.h"
 
-#if BLINK_IMPLEMENTATION
-namespace blink { struct DateTimeSuggestion; }
-#endif
-
 namespace blink {
 
+struct DateTimeSuggestion;
+
 struct WebDateTimeSuggestion {
     double value;
     WebString localizedValue;
@@ -42,8 +40,8 @@ struct WebDateTimeSuggestion {
     WebDateTimeSuggestion() { }
 
 #if BLINK_IMPLEMENTATION
-    WebDateTimeSuggestion(const blink::DateTimeSuggestion&);
-    WebDateTimeSuggestion& operator=(const blink::DateTimeSuggestion&);
+    WebDateTimeSuggestion(const DateTimeSuggestion&);
+    WebDateTimeSuggestion& operator=(const DateTimeSuggestion&);
 #endif
 };