download_actuals.py: download JSON files from Google Storage instead of skia-autogen

uses google-api-python-client instead of gsutil binary to interact with Google Storage

BUG=skia:553
R=rmistry@google.com, bensong@google.com

Author: epoger@google.com

Review URL: https://codereview.chromium.org/309653005
diff --git a/DEPS b/DEPS
index c27c9a7..97e755e 100644
--- a/DEPS
+++ b/DEPS
@@ -1,11 +1,6 @@
 use_relative_paths = True
 
-# Dependencies on outside packages, as needed for developers/bots that use
-# "gclient" instead of raw SVN access.
-#
-# For now, this must be maintained in parallel with "SVN externals"
-# dependencies for developers who use raw SVN instead of "gclient".
-# See third_party/externals/README
+# Dependencies on outside packages.
 #
 deps = {
   # DEPS using https://chromium.googlesource.com are pulled from chromium @ r205199
@@ -13,6 +8,7 @@
   "third_party/externals/angle" : "https://chromium.googlesource.com/external/angleproject.git",
   "third_party/externals/angle2" : "https://chromium.googlesource.com/angle/angle.git@bdc9b2f0ed9e365bf5a4d19799d93a512f07dd32",
   "third_party/externals/freetype" : "https://skia.googlesource.com/third_party/freetype2.git@VER-2-5-0-1",
+  "third_party/externals/google-api-python-client" : "https://github.com/google/google-api-python-client.git@56557e2c1d2cbce0d2de26e3a7f32f836b8f5eb2",
   "third_party/externals/gyp" : "https://chromium.googlesource.com/external/gyp.git@5917c6a6b77c9e97a0cbb66847194381bd36ec4c",
   "third_party/externals/libjpeg" : "https://chromium.googlesource.com/chromium/deps/libjpeg_turbo.git@82ce8a6d4ebe12a177c0c3597192f2b4f09e81c3",
   "third_party/externals/jsoncpp" : "https://chromium.googlesource.com/external/jsoncpp/jsoncpp.git@ab1e40f3bce061ea6f9bdc60351d6cde2a4f872b",