This augments the standalone and in-Chromium models with an external
model, in which the dependencies and Crashpad are checked out as
siblings in the same directory, organized according to this structure:
root/crashpad[/README]
root/gmock[/include/gmock/gmock.h]
root/gtest[/include/gtest/gtest.h]
root/gyp[/pylib/gyp]
root/mini_chromium[/build/common.gypi]
This is the directory structure used in google3.
Change-Id: Ie300ead7cd085265933e4ed891509ce050e995e2
Reviewed-on: https://chromium-review.googlesource.com/324230
Reviewed-by: Robert Sesek <rsesek@chromium.org>
Reviewed-by: Scott Graham <scottmg@chromium.org>