Revert 149417 - This broke official buildspec creation.

Revert 149417 - This broke official buildspec creation.

Revert 149244 - Exclude parts of the tree that aren't needed for iOS

This is essentially re-landing the reverted portion of
  https://chromiumcodereview.appspot.com/10704040
now that deps2git doesn't choke on None entries.

BUG=None


Review URL: https://chromiumcodereview.appspot.com/10828095

TBR=stuartmorgan@chromium.org
Review URL: https://chromiumcodereview.appspot.com/10829123

TBR=dharani@chromium.org
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=149419