Make the edge where BackgroundGradientView draws a divider selectable.

chrome/browser/ui/cocoa/background_gradient_view.h

Index: chrome/browser/ui/cocoa/background_gradient_view.h
diff --git a/chrome/browser/ui/cocoa/background_gradient_view.h b/chrome/browser/ui/cocoa/background_gradient_view.h
index 433fe1f590f7e9ce55516c2e984c8f8b2f084512..2c205a611c282d58fefc0632c52430bfea77545d 100644
--- a/chrome/browser/ui/cocoa/background_gradient_view.h
+++ b/chrome/browser/ui/cocoa/background_gradient_view.h
@@ -11,14 +11,14 @@
 
 // A custom view that draws a 'standard' background gradient.
 // Base class for other Chromium views.
-@interface BackgroundGradientView : NSView<ThemedWindowDrawing> {
- @private
-  BOOL showsDivider_;
-}
+@interface BackgroundGradientView : NSView<ThemedWindowDrawing>
 
-// Controls whether the bar draws a dividing line at the bottom.
+// Controls whether the bar draws a dividing line.
 @property(nonatomic, assign) BOOL showsDivider;
 
+// Controls where the bar draws a dividing line.
+@property(nonatomic, assign) NSRectEdge dividerEdge;
+
 // The color used for the bottom stroke. Public so subclasses can use.
 - (NSColor*)strokeColor;