X11: Fix use-of-uninitialized-variable

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 1365 matching lines @@
   return base::Singleton<XVisualManager>::get();
 }
 
 XVisualManager::XVisualManager()
     : display_(gfx::GetXDisplay()),
       default_visual_id_(0),
       system_visual_id_(0),
       transparent_visual_id_(0),
       using_software_rendering_(false),
       have_gpu_argb_visual_(false) {
-  int visuals_len;
+  int visuals_len = 0;
   XVisualInfo visual_template;
   visual_template.screen = DefaultScreen(display_);
   gfx::XScopedPtr<XVisualInfo[]> visual_list(XGetVisualInfo(
       display_, VisualScreenMask, &visual_template, &visuals_len));
   for (int i = 0; i < visuals_len; ++i)
     visuals_[visual_list[i].visualid].reset(new XVisualData(visual_list[i]));
 
   XAtom NET_WM_CM_S0 = XInternAtom(display_, "_NET_WM_CM_S0", False);
   using_compositing_wm_ = XGetSelectionOwner(display_, NET_WM_CM_S0) != None;
 
@@ skipping 84 matching lines @@
                                 visual_info.visual, AllocNone);
   }
   return colormap_;
 }
 
 // ----------------------------------------------------------------------------
 // End of x11_util_internal.h
 
 
 }  // namespace ui