mac: Remove code that was only needed on 10.5

chrome/browser/ui/cocoa/tracking_area.h

Index: chrome/browser/ui/cocoa/tracking_area.h
diff --git a/chrome/browser/ui/cocoa/tracking_area.h b/chrome/browser/ui/cocoa/tracking_area.h
index b044e4d10d5c61ec787480a962d4c851ccdcc27f..a1036ea13e42bab079c7e648913dd5b1b525360a 100644
--- a/chrome/browser/ui/cocoa/tracking_area.h
+++ b/chrome/browser/ui/cocoa/tracking_area.h
@@ -20,16 +20,9 @@
 
 // Designated initializer. Forwards all arguments to the superclass, but wraps
 // |owner| in a proxy object.
-//
-// The |proxiedOwner:| paramater has been renamed due to an incompatiblity with
-// the 10.5 SDK. Since that SDK version declares |-[NSTrackingArea's init...]|'s
-// return type to be |NSTrackingArea*| rather than |id|, a more generalized type
-// can't be returned by the subclass. Until the project switches to the 10.6 SDK
-// (where Apple changed the return type to |id|), this ugly hack must exist.
-// TODO(rsesek): Remove this when feasabile.
 - (id)initWithRect:(NSRect)rect
            options:(NSTrackingAreaOptions)options
-      proxiedOwner:(id)owner  // 10.5 SDK hack. Remove at some point.
+             owner:(id)owner
           userInfo:(NSDictionary*)userInfo;
 
 // Prevents any future messages from being delivered to the |owner|.