MacViews: Fix window dragging on Sierra.

ui/views/cocoa/views_nswindow_delegate.h

Index: ui/views/cocoa/views_nswindow_delegate.h
diff --git a/ui/views/cocoa/views_nswindow_delegate.h b/ui/views/cocoa/views_nswindow_delegate.h
index 715af24dec96201cb3d9b029c4bee38f964f917f..e9f4d7f0e5cddfc3be47d80c2085a75ff8058f30 100644
--- a/ui/views/cocoa/views_nswindow_delegate.h
+++ b/ui/views/cocoa/views_nswindow_delegate.h
@@ -55,13 +55,6 @@ VIEWS_EXPORT
 - (void)windowDidFailToEnterFullScreen:(NSWindow*)window;
 - (void)windowDidFailToExitFullScreen:(NSWindow*)window;
 
-// Called when the application receives a mouse-down, but before the event
-// is processed by NSWindows. Returns NO if the event should be processed as-is,
-// or YES if the event should be reposted to handle window dragging. Events are
-// reposted at the CGSessionEventTap level because window dragging happens there
-// before the application receives the event.
-- (BOOL)shouldRepostPendingLeftMouseDown:(NSPoint)locationInWindow;
-
 @end
 
 #endif  // UI_VIEWS_COCOA_VIEWS_NSWINDOW_DELEGATE_H_