Revert 31814 - Testing to see if it caused performance problems....

chrome/browser/cocoa/tab_view.mm

Index: chrome/browser/cocoa/tab_view.mm
===================================================================
--- chrome/browser/cocoa/tab_view.mm	(revision 31854)
+++ chrome/browser/cocoa/tab_view.mm	(working copy)
@@ -116,28 +116,6 @@
   }
 }
 
-// The tracking areas have been moved. Make sure that the close button is
-// highlighting correctly with respect to the cursor position with the new
-// tracking area locations.
-- (void)updateTrackingAreas {
-  [super updateTrackingAreas];
-
-  // Update the close buttons if the tab has moved.
-  NSPoint mouseLoc = [[self window] mouseLocationOutsideOfEventStream];
-  mouseLoc = [self convertPointFromBase:mouseLoc];
-  NSString* name = nil;
-  if (NSPointInRect(mouseLoc, [closeButton_ frame])) {
-    name = @"close_bar_h.pdf";
-  } else {
-    name = @"close_bar.pdf";
-  }
-  NSImage* newImage = nsimage_cache::ImageNamed(name);
-  NSImage* buttonImage = [closeButton_ image];
-  if (![buttonImage isEqual:newImage]) {
-    [closeButton_ setImage:newImage];
-  }
-}
-
 // Determines which view a click in our frame actually hit. It's either this
 // view or our child close button.
 - (NSView*)hitTest:(NSPoint)aPoint {