mac: Remove IsOSLion().

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

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #import "chrome/browser/ui/cocoa/tabs/tab_strip_drag_controller.h"
 
 #include <Carbon/Carbon.h>
 
 #include "base/mac/scoped_cftyperef.h"
 #import "base/mac/sdk_forward_declarations.h"
@@ skipping 193 matching lines @@
       // in the tab strip.
       CGFloat tabWidthBeyondRightEdge =
           MAX(NSMaxX(newTabFrame) - [tabStrip_ tabAreaRightEdge], 0.0);
       if (tabWidthBeyondRightEdge) {
         // Adjust the tab's x-origin so that it just touches the right edge of
         // the tab area.
         newTabFrame.origin.x -= tabWidthBeyondRightEdge;
         // Offset the new window's drag location so that the tab will still be
         // positioned correctly beneath the mouse (being careful to convert the
         // view frame offset to screen coordinates).
-        if (base::mac::IsOSLionOrLater()) {
-          NSWindow* tabViewWindow = [[draggedTab_ tabView] window];
-          horizDragOffset_ = [tabViewWindow convertRectToScreen:
-              NSMakeRect(0.0, 0.0, tabWidthBeyondRightEdge, 1.0)].size.width;
-        } else {
-          horizDragOffset_ = tabWidthBeyondRightEdge;
-        }
+        NSWindow* tabViewWindow = [[draggedTab_ tabView] window];
+        horizDragOffset_ = [tabViewWindow convertRectToScreen:
+            NSMakeRect(0.0, 0.0, tabWidthBeyondRightEdge, 1.0)].size.width;
       }
 
       [[draggedTab_ tabView] setFrameOrigin:newTabFrame.origin];
   } else {
       // Still dragging within the tab strip, wait for the next drag event.
       return;
     }
   }
 
   NSPoint thisPoint = [NSEvent mouseLocation];
@@ skipping 328 matching lines @@
     [[targetController_ window] makeMainWindow];
   } else {
     [dragWindow_ setAlphaValue:0.5];
     [[draggedController_ overlayWindow] setHasShadow:NO];
     [[draggedController_ window] makeMainWindow];
   }
   chromeIsVisible_ = shouldBeVisible;
 }
 
 @end