NaCl: Update revision in DEPS, r6490 -> r6499

DEPS

 vars = {
   # Use this googlecode_url variable only if there is an internal mirror for it.
   # If you do not know, use the full path while defining your new deps entry.
   "googlecode_url": "http://%s.googlecode.com/svn",
   "webkit_trunk": "http://svn.webkit.org/repository/webkit/trunk",
   "nacl_trunk": "http://src.chromium.org/native_client/trunk",
   "webkit_revision": "93421",
   "chromium_git": "http://git.chromium.org/git",
   "swig_revision": "69281",
   # These hashes need to be updated when nacl_revision is changed.
   # After changing nacl_revision, run 'gclient runhooks' to get the new values.
-  "nacl_irt_hash_x86_32": "a5631aadc6bb814b208f7b6078f314e62953917f",
-  "nacl_irt_hash_x86_64": "71d090b7d254836495c248a655c8f6c6ef6c58bf",
-  "nacl_revision": "6490",
+  "nacl_irt_hash_x86_32": "3da71eefa07c815a1aed9dc3a379fc41efda4b6b",
+  "nacl_irt_hash_x86_64": "147077c09e87ff2db20d32af2054bfb4de343c20",
+  "nacl_revision": "6499",
   # After changing nacl_revision, run 'glient sync' and check native_client/DEPS
   # to update other nacl_*_revision's.
   # TODO(brettw) We should use the "From" syntax to avoid hardcoding the
   # revisions here, but it makes checkdeps confused. We should fix checkdeps.
   "nacl_chrome_ppapi_revision": "97134", # native_client/DEPS: chrome_ppapi_rev 
   "nacl_tools_revision": "5360",  # native_client/DEPS: tools_rev
 
   # These hashes need to be updated when nacl_toolchain_revision is changed.
   # After changing nacl_toolchain_revision, run 'gclient runhooks' to get the
   # new values.
@@ skipping 409 matching lines @@
          "--nacl-newlib-only",
          "--file-hash", "mac_x86_newlib",
              Var("nacl_toolchain_mac_x86_newlib_hash"),
          "--file-hash", "win_x86_newlib",
              Var("nacl_toolchain_win_x86_newlib_hash"),
          "--file-hash", "linux_x86_newlib",
              Var("nacl_toolchain_linux_x86_newlib_hash"),
     ],
   },
 ]