Mac: Restore the show animation and subpixel AA for extension permissions prompts

chrome/browser/ui/cocoa/extensions/extension_install_view_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/extensions/extension_install_view_controller.h"
 
 #include "base/auto_reset.h"
 #include "base/i18n/rtl.h"
 #include "base/mac/bundle_locations.h"
 #include "base/mac/mac_util.h"
@@ skipping 259 matching lines @@
 
 - (IBAction)cancel:(id)sender {
   delegate_->InstallUIAbort(/*user_initiated=*/true);
 }
 
 - (IBAction)ok:(id)sender {
   delegate_->InstallUIProceed();
 }
 
 - (void)awakeFromNib {
+  // Since linking to 10.10, |outlineView_| needs an explicit background to
+  // ensure subpixel antialiasing is enabled for the permissions text. At the
+  // same time, the animation that shows the prompt breaks whenever the scroll
+  // view is present. Giving the scroll view a layer restores the animation, and
+  // since its contents has an opaque background, subpixel AA isn't affected.
+  [[outlineView_ enclosingScrollView] setWantsLayer:YES];
+  [outlineView_ setBackgroundColor:[NSColor whiteColor]];
+
   // Set control labels.
   [titleField_ setStringValue:base::SysUTF16ToNSString(
       prompt_->GetDialogTitle())];
   NSRect okButtonRect;
   base::string16 acceptButtonLabel = prompt_->GetAcceptButtonLabel();
   if (!acceptButtonLabel.empty()) {
     [okButton_ setTitle:base::SysUTF16ToNSString(acceptButtonLabel)];
   } else {
     [okButton_ removeFromSuperview];
     okButtonRect = [okButton_ frame];
@@ skipping 554 matching lines @@
 }
 
 - (void)accessibilityPerformAction:(NSString*)action {
   if ([action isEqualToString:NSAccessibilityPressAction])
     [self handleLinkClicked];
   else
     [super accessibilityPerformAction:action];
 }
 
 @end