mac: Pixel-based click detection for the tab close button

chrome/browser/ui/cocoa/tabs/tab_view.mm

Index: chrome/browser/ui/cocoa/tabs/tab_view.mm
diff --git a/chrome/browser/ui/cocoa/tabs/tab_view.mm b/chrome/browser/ui/cocoa/tabs/tab_view.mm
index 3657ca602293a0269140473c09d903884e32137d..5677d640d7b2c9bb173f81ed66136645f5986a57 100644
--- a/chrome/browser/ui/cocoa/tabs/tab_view.mm
+++ b/chrome/browser/ui/cocoa/tabs/tab_view.mm
@@ -147,8 +147,12 @@ const CGFloat kRapidCloseDist = 2.5;
 // view or our child close button.
 - (NSView*)hitTest:(NSPoint)aPoint {
   NSPoint viewPoint = [self convertPoint:aPoint fromView:[self superview]];
-  if (![closeButton_ isHidden])
-    if (NSPointInRect(viewPoint, [closeButton_ frame])) return closeButton_;
+  if (![closeButton_ isHidden]) {
+    if (NSPointInRect(viewPoint,[closeButton_ frame]) &&
+        [closeButton_ hitTest:viewPoint]) {
+      return closeButton_;
+    }
+  }
 
   NSRect pointRect = NSMakeRect(viewPoint.x, viewPoint.y, 1, 1);