[Mac] Reverse back/forward toolbar buttons in RTL

chrome/browser/ui/cocoa/toolbar/toolbar_button_cocoa.mm

 // Copyright (c) 2011 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/toolbar/toolbar_button_cocoa.h"
 
 #include "base/mac/foundation_util.h"
 #include "base/mac/sdk_forward_declarations.h"
 #import "chrome/browser/ui/cocoa/image_button_cell.h"
+#import "chrome/browser/ui/cocoa/l10n_util.h"
 #import "chrome/browser/ui/cocoa/view_id_util.h"
 #include "skia/ext/skia_utils_mac.h"
 #import "ui/base/cocoa/nsview_additions.h"
 #include "ui/base/material_design/material_design_controller.h"
 #include "ui/base/theme_provider.h"
 #include "ui/gfx/image/image_skia_util_mac.h"
 #include "ui/gfx/paint_vector_icon.h"
 
 namespace {
 
@@ skipping 177 matching lines @@
 }
 
 - (void)drawFocusRingMask {
   // Match the hover image's bezel.
   [[NSBezierPath bezierPathWithRoundedRect:NSInsetRect([self bounds], 2, 2)
                                    xRadius:2
                                    yRadius:2] fill];
 }
 
 - (gfx::VectorIconId)vectorIconId {
+  BOOL isRTL = cocoa_l10n_util::ShouldDoExperimentalRTLLayout();
   switch ([self viewID]) {
     case VIEW_ID_BACK_BUTTON:
-      return gfx::VectorIconId::NAVIGATE_BACK;
+      return isRTL ? gfx::VectorIconId::NAVIGATE_FORWARD
+                   : gfx::VectorIconId::NAVIGATE_BACK;
     case VIEW_ID_FORWARD_BUTTON:
-      return gfx::VectorIconId::NAVIGATE_FORWARD;
+      return isRTL ? gfx::VectorIconId::NAVIGATE_BACK
+                   : gfx::VectorIconId::NAVIGATE_FORWARD;
     case VIEW_ID_HOME_BUTTON:
       return gfx::VectorIconId::NAVIGATE_HOME;
     case VIEW_ID_APP_MENU:
       return gfx::VectorIconId::BROWSER_TOOLS;
     default:
       break;
   }
 
   return gfx::VectorIconId::VECTOR_ICON_NONE;
 }
@@ skipping 152 matching lines @@
 
 - (void)windowDidChangeTheme {
   // Update the hover and pressed image backgrounds to match the current theme.
   [self resetButtonStateImages];
 }
 
 - (void)windowDidChangeActive {
 }
 
 @end