Added PRESUBMIT.py for binary_size tools.

Added PRESUBMIT.py for binary_size tools.

Make the tests run for every commit to make sure tests and code
stay in sync and are both working.

BUG=

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=272496

[Andrew Hayden (chromium.org), 2014-05-21 14:36:04]

LGTM. And once again, thank you for taking this on. It's great to have some help
on this.

[Primiano Tucci (use gerrit), 2014-05-22 09:30:38]

Thanks again for doing this!

This can be simplified a bit taking advantage of the magic that we already have.
I added some comments inline below.

However, it turned out to be easier to copy/paste/replace, so
http://crrev.com/296113006 is pretty much how it should look like and should
save us some roundtrip time ;-)

Also please note that now that you have a PRESUBMIT you have also some lints :)
(that is exactly what PRESUBMIT is for)

They're uber trivial to fix, though:

F0401: 39,0: Unable to import 'symbols.elf_symbolizer'
W0622: 43,16:FormatBytes: Redefining built-in 'bytes'
W0622: 55,22:SymbolTypeToHuman: Redefining built-in 'type'
W0622:175,11:TreeifySymbols: Redefining built-in 'type'
C0323:225,8:TreeifySymbols: Operator not followed by a space
        print >>sys.stderr, sym, parts, file_key
               ^
C0321:271,32:JsonifyTree: More than one statement on a single line
W0622:310,13:DumpLargestSymbols: Redefining built-in 'type'
W0622:348,2:DumpLargestSources: Redefining built-in 'map'
W0622:372,14:DumpLargestVTables: Redefining built-in 'type'
W0612:372,14:DumpLargestVTables: Unused variable 'type'

https://codereview.chromium.org/296003007/diff/1/tools/binary_size/PRESUBMIT.py
File tools/binary_size/PRESUBMIT.py (right):

https://codereview.chromium.org/296003007/diff/1/tools/binary_size/PRESUBMIT....
tools/binary_size/PRESUBMIT.py:1: #!/usr/bin/env python
The PRESUBMIT.py shouldn't have a shbang and should not be executable (e.g.
chmod a-x before reuploading)

https://codereview.chromium.org/296003007/diff/1/tools/binary_size/PRESUBMIT....
tools/binary_size/PRESUBMIT.py:12: def _RunUnitTests(input_api, output_api):
Is there an actual reason why you didn't just copy over the one from deps2git as
I suggested you in the previous CL?
I didn't just pick a random one. I suggested that one because that is well done!
:)

https://codereview.chromium.org/296003007/diff/1/tools/binary_size/PRESUBMIT....
tools/binary_size/PRESUBMIT.py:15: input_api.PresubmitLocalPath(),
'explain_binary_size_delta_unittest.py')
We already have the mechanisms in place to run discover and run unittests, no
need to hard code the file name here (again, see deps2git).

https://codereview.chromium.org/296003007/diff/1/tools/binary_size/PRESUBMIT....
tools/binary_size/PRESUBMIT.py:17: if input_api.platform == 'win32':
Neither we need platform specific black magic.

https://codereview.chromium.org/296003007/diff/1/tools/binary_size/explain_bi...
File tools/binary_size/explain_binary_size_delta_unittest.py (right):

https://codereview.chromium.org/296003007/diff/1/tools/binary_size/explain_bi...
tools/binary_size/explain_binary_size_delta_unittest.py:9: import sys
you can import unittest and use it, as all the other unittests do.
THis will avoid you handling the hand crafted diff magic (see below).

https://codereview.chromium.org/296003007/diff/1/tools/binary_size/explain_bi...
tools/binary_size/explain_binary_size_delta_unittest.py:14: def TestCompare():
This should be
class TestCompare(unittest.TestCase):
  def runTest(self):

https://codereview.chromium.org/296003007/diff/1/tools/binary_size/explain_bi...
tools/binary_size/explain_binary_size_delta_unittest.py:79: assert
('/file_unchanged', 't', 'unchanged', 1000, 1000) in unchanged
When you switch to python unittests, you could take advantage here of
self.assertIn (is just more verbose and more explicative in the cases the
assertion fails).
Don't feel personally strong against just assert, though, so do as you prefer.

https://codereview.chromium.org/296003007/diff/1/tools/binary_size/explain_bi...
tools/binary_size/explain_binary_size_delta_unittest.py:193: if result !=
expected_output:
Lines 193-198 can be simply rewritten as:
self.assertEqual(result.splitlines(), expected_output.splitlines())

Power of python modules ;-)

https://codereview.chromium.org/296003007/diff/1/tools/binary_size/explain_bi...
tools/binary_size/explain_binary_size_delta_unittest.py:204: def main():
remove this.
Python unittests can already auto-discover test cases.

https://codereview.chromium.org/296003007/diff/1/tools/binary_size/explain_bi...
tools/binary_size/explain_binary_size_delta_unittest.py:210: sys.exit(main())
s/sys.exit(main())/unittest.main()/

[Andrew Hayden (chromium.org), 2014-05-22 09:48:35]

FWIW I think I should have had Primiano review the code I originally wrote :)

[Primiano Tucci (use gerrit), 2014-05-22 19:02:34]

LGTM. Thanks for adding the presubmit.
I appreciate the patience.

https://codereview.chromium.org/296003007/diff/40001/tools/binary_size/explai...
File tools/binary_size/explain_binary_size_delta_unittest.py (right):

https://codereview.chromium.org/296003007/diff/40001/tools/binary_size/explai...
tools/binary_size/explain_binary_size_delta_unittest.py:13: 
Nit: add extra line here

https://codereview.chromium.org/296003007/diff/40001/tools/binary_size/run_bi...
File tools/binary_size/run_binary_size_analysis.py (right):

https://codereview.chromium.org/296003007/diff/40001/tools/binary_size/run_bi...
tools/binary_size/run_binary_size_analysis.py:39: import symbols.elf_symbolizer
as elf_symbolizer # pylint: disable=F0401
Nit: add extra space here before the "#"
(PEP-8: Inline comments should be separated by at least two spaces from the
statement.)

[Daniel Bratell, 2014-05-23 05:58:26]

The CQ bit was checked by bratell@opera.com

[commit-bot: I haz the power, 2014-05-23 05:58:52]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/bratell@opera.com/296003007/80001

[commit-bot: I haz the power, 2014-05-23 11:40:40]

Change committed as 272496