Make Angle available for iOS (for Chromoting iOS client)

BUG=134226

Review URL: https://codereview.chromium.org/469953002

Cr-Commit-Position: refs/heads/master@{#289550}
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@289550 0039d316-1c4b-4281-b951-d872f2087c98

DEPS

@@ -401,7 +401,6 @@ deps_os = {
     "src/media/cdm/ppapi/api": None,
     "src/native_client": None,
     "src/native_client/src/third_party/ppapi": None,
-    "src/third_party/angle": None,
     "src/third_party/bidichecker": None,
     "src/third_party/brotli/src": None,
     "src/third_party/cld_2/src": None,