[Mac] Move ScopedSendingEvent from content/common/mac to base/mac.

chrome/browser/tab_contents/tab_contents_view_mac.mm

Index: chrome/browser/tab_contents/tab_contents_view_mac.mm
diff --git a/chrome/browser/tab_contents/tab_contents_view_mac.mm b/chrome/browser/tab_contents/tab_contents_view_mac.mm
index ff7ce924c9a80f0e8fdf0de35b5c03d4e05c2c80..121e0824e46e192e64f7f0844038dfdb395a55f8 100644
--- a/chrome/browser/tab_contents/tab_contents_view_mac.mm
+++ b/chrome/browser/tab_contents/tab_contents_view_mac.mm
@@ -8,6 +8,7 @@
 
 #include <string>
 
+#import "base/mac/scoped_sending_event.h"
 #import "chrome/browser/renderer_host/chrome_render_widget_host_view_mac_delegate.h"
 #include "chrome/browser/tab_contents/render_view_context_menu_mac.h"
 #include "chrome/browser/tab_contents/web_drag_bookmark_handler_mac.h"
@@ -23,7 +24,6 @@
 #import "content/browser/tab_contents/web_drag_dest_mac.h"
 #import "content/browser/tab_contents/web_drag_source_mac.h"
 #import "content/common/chrome_application_mac.h"
-#import "content/common/mac/scoped_sending_event.h"
 #include "content/common/view_messages.h"
 #include "skia/ext/skia_utils_mac.h"
 #import "third_party/mozilla/NSPasteboard+Utils.h"
@@ -172,7 +172,7 @@ void TabContentsViewMac::StartDragging(
   // processing -sendEvent:, so Close() is deferred in that case.
   // Drags from web content do not come via -sendEvent:, this sets the
   // same flag -sendEvent: would.
-  content::mac::ScopedSendingEvent sending_event_scoper;
+  base::mac::ScopedSendingEvent sending_event_scoper;
 
   // The drag invokes a nested event loop, arrange to continue
   // processing events.