Add libc++ and libc++abi to third-party.

DEPS

 # This file is automatically processed to create .DEPS.git which is the file
 # that gclient uses under git.
 #
 # See http://code.google.com/p/chromium/wiki/UsingGit
 #
 # To test manually, run:
 #   python tools/deps2git/deps2git.py -o .DEPS.git
 #   gclient runhooks
 # DO NOT CHECK IN CHANGES TO .DEPS.git. It will be automatically updated by
 # a bot when you modify this one.
 #
 # When adding a new dependency, please update the top-level .gitignore file
 # to list the dependency's destination directory.
 
 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",
   "sourceforge_url": "http://svn.code.sf.net/p/%(repo)s/code",
+  "llvm_git": "https://llvm.googlesource.com",
+  "libcxx_revision": "8f48c23568a122de6088455700e9d197b79bd8f8",
+  "libcxxabi_revision": "753a30dd68ae008948d48f16bc942d5963fe65a1",
   "webkit_trunk": "http://src.chromium.org/blink/trunk",
   "nacl_trunk": "http://src.chromium.org/native_client/trunk",
   "webkit_revision": "164196",
   "chromium_git": "https://chromium.googlesource.com",
   "chromiumos_git": "https://chromium.googlesource.com/chromiumos",
   "skia_git": "https://skia.googlesource.com",
   "swig_revision": "230490",
   "nacl_revision": "12558",
   # After changing nacl_revision, run 'glient sync' and check native_client/DEPS
   # to update other nacl_*_revision's.
@@ skipping 71 matching lines @@
   "src/third_party/safe_browsing/testing":
     (Var("googlecode_url") % "google-safe-browsing") + "/trunk/testing@112",
 
   "src/third_party/cacheinvalidation/src":
     (Var("googlecode_url") % "google-cache-invalidation-api") +
     "/trunk/src@314",
 
   "src/third_party/leveldatabase/src":
     (Var("googlecode_url") % "leveldb") + "/trunk@78",
 
+  "src/third_party/libc++/trunk":
+    Var("llvm_git") + "/libcxx.git@" + Var("libcxx_revision"),
+
+  "src/third_party/libc++abi/trunk":
+    Var("llvm_git") + "/libcxxabi.git@" + Var("libcxxabi_revision"),
+  
   "src/third_party/snappy/src":
     (Var("googlecode_url") % "snappy") + "/trunk@80",
 
   "src/tools/grit":
     (Var("googlecode_url") % "grit-i18n") + "/trunk@140",
 
   "src/tools/gyp":
     (Var("googlecode_url") % "gyp") + "/trunk@1806",
 
   "src/tools/swarming_client":
@@ skipping 573 matching lines @@
     "pattern": ".",
     "action": ["python", "src/build/gyp_chromium"],
   },
   {
     # Check for landmines (reasons to clobber the build).
     "name": "landmines",
     "pattern": ".",
     "action": ["python", "src/build/landmines.py"],
   },
 ]