Fix javac command never caching input .md5s

This was broken over a year ago by http://crrev.com/a78eb479

This change also removes --classes-dir (which is currently unused), and makes --jar-path (always used) required.

It also forces the command to run if the output is missing (rather than relying completely on the .stamp file)

On my ubiquity machine:
Add a log statement to a file in base_java then build chrome_apk:

Before:
real    2m25.188s
user    4m52.950s
sys     1m10.064s

After:
real    1m16.989s
user    1m13.795s
sys     0m44.040s

BUG=523420, 379190

Review URL: https://codereview.chromium.org/1308083002

Cr-Commit-Position: refs/heads/master@{#346975}


CrOS-Libchrome-Original-Commit: 1c366880cb68fbf25050f1c6d78684eb6ae2e644
1 file changed
tree: 7908f0709e6a23def3bd58ce440dbfb7f80dacb3
  1. base/
  2. build/
  3. components/
  4. dbus/
  5. device/
  6. ipc/
  7. mojo/
  8. testing/
  9. third_party/
  10. ui/