Speed up shelldb by skipping unnecessary copies of APK to device
Speed up shelldb by skipping unnecessary copies of APK to device

Right now I'm storing a SHA1 in a folder in /sdcard since
that seems likely to work on non-rooted devices, but
I haven't tested it.

This cuts build times from 6.5 seconds to 1.5 seconds for
me. You can save another 0.5sec by passing the --no_install
flag to avoid the SHA1 check altogether if you're sure
that nothing has changed.

R=eseidel@chromium.org, eseidel, hixie

Review URL: https://codereview.chromium.org/1149113005

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