Add harfbuzz to DEPS

https://skia.googlesource.com/third_party/harfbuzz/

BUG=skia:3067

Review URL: https://codereview.chromium.org/679733002
diff --git a/DEPS b/DEPS
index 60cd3ff..7a0422b 100644
--- a/DEPS
+++ b/DEPS
@@ -12,6 +12,7 @@
   "third_party/externals/jsoncpp" : "https://chromium.googlesource.com/external/jsoncpp/jsoncpp.git@1afff032c83e26ddf7f2776e8b43de5ad666c1fa",
   "third_party/externals/libwebp" : "https://chromium.googlesource.com/webm/libwebp.git@3fe91635df8734b23f3c1b9d1f0c4fa8cfaf4e39",
   "third_party/externals/nanomsg": "https://skia.googlesource.com/third_party/nanomsg.git@0.4-beta",
+  "third_party/externals/harfbuzz": "https://skia.googlesource.com/third_party/harfbuzz.git@0.9.35",
 
   # The line below is needed for compiling SkV8Example. Do not delete.
   #"third_party/externals/v8": "https://chromium.googlesource.com/v8/v8.git@5f1ae66d5634e43563b2d25ea652dfb94c31a3b4",