X11: Fix broken DCHECK when no transparent visual is available

ui/base/x/x11_util.cc

 // 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.
 
 // This file defines utility functions for X11 (Linux only). This code has been
 // ported from XCB since we can't use XCB on Ubuntu while its 32-bit support
 // remains woefully incomplete.
 
 #include "ui/base/x/x11_util.h"
 
@@ skipping 1439 matching lines @@
     // gdkvisual-x11.cc, they look for this specific visual and use it for
     // all their alpha channel using needs.
     const XVisualInfo& info = pair.second->visual_info;
     if (info.depth == 32 && info.visual->red_mask == 0xff0000 &&
         info.visual->green_mask == 0x00ff00 &&
         info.visual->blue_mask == 0x0000ff) {
       transparent_visual_id_ = info.visualid;
       break;
     }
   }
-  DCHECK(transparent_visual_id_);
-  DCHECK(visuals_.find(transparent_visual_id_) != visuals_.end());
+  if (transparent_visual_id_)
+    DCHECK(visuals_.find(transparent_visual_id_) != visuals_.end());
 }
 
 XVisualManager::~XVisualManager() {}
 
 void XVisualManager::ChooseVisualForWindow(bool want_argb_visual,
                                            Visual** visual,
                                            int* depth,
                                            Colormap* colormap,
                                            bool* using_argb_visual) {
   bool use_argb = want_argb_visual && using_compositing_wm_ &&
                   (using_software_rendering_ || have_gpu_argb_visual_);
   XVisualData& visual_data =
-      *visuals_[use_argb ? transparent_visual_id_ : system_visual_id_];
+      *visuals_[use_argb && transparent_visual_id_ ? transparent_visual_id_
+                                                   : system_visual_id_];
   if (visual)
     *visual = visual_data.visual_info.visual;
   if (depth)
     *depth = visual_data.visual_info.depth;
   if (colormap)
     *colormap = visual_data.GetColormap();
   if (using_argb_visual)
     *using_argb_visual = use_argb;
 }
 
@@ skipping 31 matching lines @@
   return colormap_;
 }
 
 #endif
 
 // ----------------------------------------------------------------------------
 // End of x11_util_internal.h
 
 
 }  // namespace ui