Attempt to fix Linux ChromiumOS Ozone Builder after r290136.

BUG=
TBR=jamesr@chromium.org

Review URL: https://codereview.chromium.org/483493002

Cr-Commit-Position: refs/heads/master@{#290146}
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@290146 0039d316-1c4b-4281-b951-d872f2087c98

ui/gl/gl_surface_ozone.cc

@@ -154,7 +154,8 @@ scoped_refptr<GLSurface> GLSurface::CreateOffscreenGLSurface(
     const gfx::Size& size) {
   switch (GetGLImplementation()) {
     case kGLImplementationOSMesaGL: {
-      scoped_refptr<GLSurface> surface(new GLSurfaceOSMesa(1, size));
+      scoped_refptr<GLSurface> surface(
+          new GLSurfaceOSMesa(OSMesaSurfaceFormatBGRA, size));
       if (!surface->Initialize())
         return NULL;