Prepare ui/ module for compilation with OS X 10.7 deployment target.

ui/views/cocoa/tooltip_manager_mac.mm

Index: ui/views/cocoa/tooltip_manager_mac.mm
diff --git a/ui/views/cocoa/tooltip_manager_mac.mm b/ui/views/cocoa/tooltip_manager_mac.mm
index 3101ee13a6a076049d2f0c2a9e952dba066c68ec..99a1fb5d9069b5c8a61baa1efacb7d3389f90667 100644
--- a/ui/views/cocoa/tooltip_manager_mac.mm
+++ b/ui/views/cocoa/tooltip_manager_mac.mm
@@ -4,6 +4,7 @@
 
 #include "ui/views/cocoa/tooltip_manager_mac.h"
 
+#include "ui/base/cocoa/cocoa_base_utils.h"
 #include "ui/gfx/font_list.h"
 #import "ui/gfx/mac/coordinate_conversion.h"
 #import "ui/views/cocoa/bridged_content_view.h"
@@ -39,7 +40,8 @@ void TooltipManagerMac::UpdateTooltip() {
   NSWindow* window = widget_->ns_window();
   BridgedContentView* view = widget_->ns_view();
 
-  NSPoint nspoint = [window convertScreenToBase:[NSEvent mouseLocation]];
+  NSPoint nspoint =
+      ui::ConvertPointFromScreenToWindow(window, [NSEvent mouseLocation]);
   // Note: flip in the view's frame, which matches the window's contentRect.
   gfx::Point point(nspoint.x, NSHeight([view frame]) - nspoint.y);
   [view updateTooltipIfRequiredAt:point];