Don't put a text shadow on blue buttons in gtk theme mode.

chrome/browser/ui/libgtk2ui/native_theme_gtk2.cc

 // Copyright (c) 2013 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.
 
 #include "chrome/browser/ui/libgtk2ui/native_theme_gtk2.h"
 
 #include <gtk/gtk.h>
 
 #include "chrome/browser/ui/libgtk2ui/chrome_gtk_menu_subclasses.h"
 #include "chrome/browser/ui/libgtk2ui/gtk2_ui.h"
@@ skipping 133 matching lines @@
     case kComboboxArrow:
       PaintComboboxArrow(canvas, GetGtkState(state), rect);
       return;
 
     default:
       NativeThemeBase::Paint(canvas, part, state, rect, extra);
   }
 }
 
 SkColor NativeThemeGtk2::GetSystemColor(ColorId color_id) const {
+  if (color_id == kColorId_BlueButtonShadowColor)
+    return SK_ColorTRANSPARENT;
+
   return GdkColorToSkColor(GetSystemGdkColor(color_id));
 }
 
 void NativeThemeGtk2::PaintMenuPopupBackground(
     SkCanvas* canvas,
     const gfx::Size& size,
     const MenuBackgroundExtraParams& menu_background) const {
   if (menu_background.corner_radius > 0) {
     SkPaint paint;
     paint.setStyle(SkPaint::kFill_Style);
@@ skipping 99 matching lines @@
       return GetButtonStyle()->text[GTK_STATE_INSENSITIVE];
     case kColorId_ButtonHighlightColor:
       return GetButtonStyle()->base[GTK_STATE_SELECTED];
     case kColorId_ButtonHoverColor:
     case kColorId_BlueButtonHoverColor:
       return GetButtonStyle()->text[GTK_STATE_PRELIGHT];
     case kColorId_ButtonHoverBackgroundColor:
       return GetButtonStyle()->bg[GTK_STATE_PRELIGHT];
     case kColorId_BlueButtonPressedColor:
       return GetButtonStyle()->text[GTK_STATE_ACTIVE];
+    case kColorId_BlueButtonShadowColor:
+      // Should be handled in GetSystemColor().
+      NOTREACHED();
+      return GetButtonStyle()->text[GTK_STATE_NORMAL];
 
     // Textfield
     case kColorId_TextfieldDefaultColor:
       return GetEntryStyle()->text[GTK_STATE_NORMAL];
     case kColorId_TextfieldDefaultBackground:
       return GetEntryStyle()->base[GTK_STATE_NORMAL];
     case kColorId_TextfieldReadOnlyColor:
       return GetEntryStyle()->text[GTK_STATE_INSENSITIVE];
     case kColorId_TextfieldReadOnlyBackground:
       return GetEntryStyle()->base[GTK_STATE_INSENSITIVE];
@@ skipping 193 matching lines @@
                                                0, 0,
                                                rect.width(), rect.height());
   SkBitmap arrow = GdkPixbufToImageSkia(pb);
   canvas->drawBitmap(arrow, rect.x(), rect.y());
 
   g_object_unref(pb);
   g_object_unref(pm);
 }
 
 }  // namespace libgtk2ui