[pylib/devil] Create devil.android.base_tool and derive valgrind_tools classes from it.

This helps remove forwarder's dependency on pylib.valgrind_tools

BUG=561582

Review URL: https://codereview.chromium.org/1476723003

Cr-Commit-Position: refs/heads/master@{#361758}


CrOS-Libchrome-Original-Commit: 88c4af1e2b654dbdf64113a8c77a2210dc36b3b6
2 files changed
tree: 173a5d1c6d6070e4cd24fa18090d58136a716b26
  1. base/
  2. build/
  3. components/
  4. dbus/
  5. device/
  6. ipc/
  7. mojo/
  8. testing/
  9. third_party/
  10. ui/