[Mac][Material Design] Fix toolbar icon hover bg for custom themes.

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/view_id_util.h"
@@ skipping 276 matching lines @@
   // ivar.
   image_.reset([anImage retain]);
   [self resetButtonStateImages];
 }
 
 - (void)resetButtonStateImages {
   DCHECK(ui::MaterialDesignController::IsModeMaterial());
 
   NSImage* normalIcon = nil;
   NSImage* disabledIcon = nil;
+  BOOL isDarkTheme = NO;
 
   gfx::VectorIconId iconId = [self vectorIconId];
   if (iconId == gfx::VectorIconId::VECTOR_ICON_NONE) {
     // If the button does not have a vector icon id (e.g. it's an extension
     // button), use its image. The hover, etc. images will be created using
     // imageForIcon:withBackgroundStyle: so do the same for the default image.
     // If we don't do this, the icon may not appear in the same place as in the
     // other states, causing the icon to appear to shift as you mouse over the
     // button.
     NSImage* defaultImage =
         [self imageForIcon:[self image]
               withBackgroundStyle:ToolbarButtonImageBackgroundStyle::DEFAULT];
     normalIcon = disabledIcon = defaultImage;
   } else {
     // Compute the normal and disabled vector icon colors.
-    BOOL isDarkTheme = [[self window] hasDarkTheme];
+    isDarkTheme = [[self window] hasDarkTheme];
     const SkColor vectorIconColor = [self vectorIconColor:isDarkTheme];
     CGFloat normalAlpha = isDarkTheme ? 0xCC : 0xFF;
     const SkColor normalColor = SkColorSetA(vectorIconColor, normalAlpha);
     const SkColor disabledColor = SkColorSetA(vectorIconColor, 0x33);
 
     // Create the normal and disabled state icons. These icons are always the
     // same shape but use a different color.
     if (iconId == gfx::VectorIconId::BROWSER_TOOLS) {
       normalIcon = [self browserToolsIconForFillColor:normalColor];
       disabledIcon = [self browserToolsIconForFillColor:disabledColor];
@@ skipping 20 matching lines @@
   // Determine the appropriate image background style for the hover and pressed
   // states.
   ToolbarButtonImageBackgroundStyle hoverStyle =
       ToolbarButtonImageBackgroundStyle::HOVER;
   ToolbarButtonImageBackgroundStyle pressedStyle =
       ToolbarButtonImageBackgroundStyle::PRESSED;
 
   // Use the themed style for custom themes and Incognito mode.
   const ui::ThemeProvider* themeProvider = [[self window] themeProvider];
   bool incongitoMode = themeProvider && themeProvider->InIncognitoMode();
-  bool usingACustomTheme = themeProvider && !themeProvider->UsingSystemTheme();
-  if (usingACustomTheme || incongitoMode) {
+  if (isDarkTheme || incongitoMode) {
     hoverStyle = ToolbarButtonImageBackgroundStyle::HOVER_THEMED;
     pressedStyle = ToolbarButtonImageBackgroundStyle::PRESSED_THEMED;
   }
 
   // Create and set the hover state image.
   NSImage* hoverImage =
       [self imageForIcon:normalIcon withBackgroundStyle:hoverStyle];
   [theCell setImage:hoverImage
      forButtonState:image_button_cell::kHoverState];
 
@@ skipping 25 matching lines @@
   // Update the hover and pressed image backgrounds to match the current theme.
   if (ui::MaterialDesignController::IsModeMaterial()) {
     [self resetButtonStateImages];
   }
 }
 
 - (void)windowDidChangeActive {
 }
 
 @end