[Mac] Removes artificial location padding logic to fix a bug with browser action transparency.

chrome/browser/cocoa/extensions/browser_actions_controller.mm

 // Copyright (c) 2010 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 "browser_actions_controller.h"
 
 #include <cmath>
 #include <string>
 
 #include "base/nsimage_cache_mac.h"
@@ skipping 15 matching lines @@
 #include "chrome/common/notification_observer.h"
 #include "chrome/common/notification_registrar.h"
 #include "chrome/common/pref_names.h"
 #import "third_party/GTM/AppKit/GTMNSAnimation+Duration.h"
 
 NSString* const kBrowserActionVisibilityChangedNotification =
     @"BrowserActionVisibilityChangedNotification";
 
 namespace {
 const CGFloat kAnimationDuration = 0.2;
-// When determining the opacity during a drag, we artificially reduce the
-// distance to the edge in order to make the fade more apparent.
-const CGFloat kButtonOpacityLeadPadding = 5.0;
+
 const CGFloat kChevronWidth = 14.0;
 
 // Image used for the overflow button.
 NSString* const kOverflowChevronsName =
     @"browser_actions_overflow_Template.pdf";
 
 // Since the container is the maximum height of the toolbar, we have
 // to move the buttons up by this amount in order to have them look
 // vertically centered within the toolbar.
 const CGFloat kBrowserActionOriginYOffset = 5.0;
@@ skipping 487 matching lines @@
       continue;
     if (![button isBeingDragged])
       [self moveButton:button toIndex:i animate:animate];
     ++i;
   }
 }
 
 - (void)updateButtonOpacity {
   for (BrowserActionButton* button in [buttons_ allValues]) {
     NSRect buttonFrame = [button frame];
-    buttonFrame.origin.x += kButtonOpacityLeadPadding;
     if (NSContainsRect([containerView_ bounds], buttonFrame)) {
       if ([button alphaValue] != 1.0)
         [button setAlphaValue:1.0];
 
       continue;
     }
     CGFloat intersectionWidth =
         NSWidth(NSIntersectionRect([containerView_ bounds], buttonFrame));
-    CGFloat alpha = std::max(0.0f,
-        (intersectionWidth - kButtonOpacityLeadPadding) / NSWidth(buttonFrame));
+    CGFloat alpha = std::max(0.0f, intersectionWidth / NSWidth(buttonFrame));
     [button setAlphaValue:alpha];
     [button setNeedsDisplay:YES];
   }
 }
 
 - (BrowserActionButton*)buttonForExtension:(Extension*)extension {
   NSString* extensionId = base::SysUTF8ToNSString(extension->id());
   DCHECK(extensionId);
   if (!extensionId)
     return nil;
@@ skipping 291 matching lines @@
   if (profile_->IsOffTheRecord())
     index = toolbarModel_->IncognitoIndexToOriginal(index);
   if (index < toolbarModel_->size()) {
     Extension* extension = toolbarModel_->GetExtensionByIndex(index);
     return [buttons_ objectForKey:base::SysUTF8ToNSString(extension->id())];
   }
   return nil;
 }
 
 @end