Fix android_finder.py

Fix ahe's feedback.

+ Define a util.Error class and use it instead of a raw Exception

+ Periods at the end of sentences in comments and error messages.

+ Destructuring assignment for working with tupples.

BUG=

Committed: https://code.google.com/p/dart/source/detail?r=11667

[jackpal, 2012-08-30 18:38:10]

This is my response to Peter's review of android_finder.py

(I can't figure out how to cleanly modify the original CL now that it's
committed, so I am starting a new CL to address Peter's comments.)

[ahe, 2012-08-30 20:11:07]

LGTM!

You shouldn't modify the original CL. That's done now.

Cheers,
Peter

http://codereview.chromium.org/10916021/diff/1/runtime/tools/android_finder.py
File runtime/tools/android_finder.py (right):

http://codereview.chromium.org/10916021/diff/1/runtime/tools/android_finder.p...
runtime/tools/android_finder.py:98: and
package_description.find(key_description_prefix) == 0):
startswith?

[jackpal, 2012-08-30 23:07:24]

http://codereview.chromium.org/10916021/diff/1/runtime/tools/android_finder.py
File runtime/tools/android_finder.py (right):

http://codereview.chromium.org/10916021/diff/1/runtime/tools/android_finder.p...
runtime/tools/android_finder.py:98: and
package_description.find(key_description_prefix) == 0):
On 2012/08/30 20:11:07, ahe wrote:
> startswith?

Done.