Fix (or tag) uses of explicit '64' instead of GL_MAILBOX_SIZE_CHROMIUM

cc/test/test_web_graphics_context_3d.cc

 // Copyright 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 "cc/test/test_web_graphics_context_3d.h"
 
 #include <algorithm>
 #include <string>
 
 #include "base/bind.h"
@@ skipping 418 matching lines @@
 
 void TestWebGraphicsContext3D::genMailboxCHROMIUM(GLbyte* mailbox) {
   if (times_gen_mailbox_succeeds_ >= 0) {
     if (!times_gen_mailbox_succeeds_) {
       loseContextCHROMIUM(GL_GUILTY_CONTEXT_RESET_ARB,
                           GL_INNOCENT_CONTEXT_RESET_ARB);
     }
     --times_gen_mailbox_succeeds_;
   }
   if (context_lost_) {
-    memset(mailbox, 0, 64);
+    memset(mailbox, 0, GL_MAILBOX_SIZE_CHROMIUM);
     return;
   }
 
   static char mailbox_name1 = '1';
   static char mailbox_name2 = '1';
   mailbox[0] = mailbox_name1;
   mailbox[1] = mailbox_name2;
   mailbox[2] = '\0';
   if (++mailbox_name1 == 0) {
     mailbox_name1 = '1';
@@ skipping 295 matching lines @@
 
 TestWebGraphicsContext3D::Buffer::Buffer() : target(0), size(0) {}
 
 TestWebGraphicsContext3D::Buffer::~Buffer() {}
 
 TestWebGraphicsContext3D::Image::Image() {}
 
 TestWebGraphicsContext3D::Image::~Image() {}
 
 }  // namespace cc