x11: Use scoped_ptr<> for X11 objects where it makes sense.

ui/gfx/x/x11_types.cc

Index: ui/gfx/x/x11_types.cc
diff --git a/ui/gfx/x/x11_types.cc b/ui/gfx/x/x11_types.cc
index 54a0816c65236121dd6852a21a87777f03b43efb..e74129e216a77cc8d2bd80c45c5f45a39fcc3672 100644
--- a/ui/gfx/x/x11_types.cc
+++ b/ui/gfx/x/x11_types.cc
@@ -45,20 +45,16 @@ void PutARGBImage(XDisplay* display,
 
 int BitsPerPixelForPixmapDepth(XDisplay* dpy, int depth) {
   int count;
-  XPixmapFormatValues* formats = XListPixmapFormats(dpy, &count);
+  XScopedPtr<XPixmapFormatValues[]> formats(XListPixmapFormats(dpy, &count));
   if (!formats)
     return -1;
 
-  int bits_per_pixel = -1;
   for (int i = 0; i < count; ++i) {
-    if (formats[i].depth == depth) {
-      bits_per_pixel = formats[i].bits_per_pixel;
-      break;
-    }
+    if (formats[i].depth == depth)
+      return formats[i].bits_per_pixel;
   }
 
-  XFree(formats);
-  return bits_per_pixel;
+  return -1;
 }
 
 void PutARGBImage(XDisplay* display,