Refactor emma_instr.py in preparation for porting EMMA GYP rules to GN

Refactor emma_instr.py in preparation for porting EMMA GYP rules to GN

Notable changes:
- 'coverage_file' & 'sources_list_file' arguments now take complete paths
- 'sources' argument renamed to 'source_dirs'
- 'source_files' argument added which takes in a list of source Java files
- 'depfile' argument added

BUG=535290
Cr-Commit-Position: refs/heads/master@{#359980}

Committed: https://crrev.com/17ec244eb92d303b49b3f89eace52ac38d3698d5
Cr-Commit-Position: refs/heads/master@{#360376}

[pkotwicz, 2015-11-18 00:07:07]

Description was changed from

==========
Refactor emma_instr.py in preparation for porting EMMA build rules to GN

Notable changes:
- 'coverage_file' & 'sources_list_file' arguments now take complete paths
- 'sources' argument renamed to 'source_dirs'
- 'source_files' argument added which takes in a list of source Java files
- 'depfile' argument added

BUG=535290

Cr-Commit-Position: refs/heads/master@{#359980}
==========

to

==========
Refactor emma_instr.py in preparation for porting EMMA GYP rules to GN

Notable changes:
- 'coverage_file' & 'sources_list_file' arguments now take complete paths
- 'sources' argument renamed to 'source_dirs'
- 'source_files' argument added which takes in a list of source Java files
- 'depfile' argument added

BUG=535290

Cr-Commit-Position: refs/heads/master@{#359980}
==========

[pkotwicz, 2015-11-18 00:10:03]

pkotwicz@chromium.org changed reviewers:
+ agrieve@chromium.org

[pkotwicz, 2015-11-18 00:10:03]

agrieve@ PTAL

[pkotwicz, 2015-11-18 00:13:16]

Patchset #1 (id:1) has been deleted

[agrieve, 2015-11-18 15:30:47]

just nits. lgtm

https://codereview.chromium.org/1448223004/diff/40001/build/android/gyp/emma_...
File build/android/gyp/emma_instr.py (right):

https://codereview.chromium.org/1448223004/diff/40001/build/android/gyp/emma_...
build/android/gyp/emma_instr.py:116: source_dirs = set()
nit: More concise: return list(set(os.path.dirname(p) for p in source_files))

https://codereview.chromium.org/1448223004/diff/40001/build/android/gyp/emma_...
build/android/gyp/emma_instr.py:184: print('Error: multiple output files in: %s'
% (temp_jar_dir))
you should raise an exception rather than explicitly returning an error code:

raise Exception(msg)

https://codereview.chromium.org/1448223004/diff/40001/build/android/gyp/emma_...
build/android/gyp/emma_instr.py:191: source_dirs = []
no need to initialize since it's re-assigned in both branches

https://codereview.chromium.org/1448223004/diff/40001/build/android/gyp/emma_...
build/android/gyp/emma_instr.py:197: options.src_root)
nit: indent is off

[pkotwicz, 2015-11-18 15:59:28]

https://codereview.chromium.org/1448223004/diff/40001/build/android/gyp/emma_...
File build/android/gyp/emma_instr.py (right):

https://codereview.chromium.org/1448223004/diff/40001/build/android/gyp/emma_...
build/android/gyp/emma_instr.py:116: source_dirs = set()
It might be because I am relatively new to Python, but I find Python shorthand
to hard to read

https://codereview.chromium.org/1448223004/diff/40001/build/android/gyp/emma_...
build/android/gyp/emma_instr.py:184: print('Error: multiple output files in: %s'
% (temp_jar_dir))
This way of handling exceptions is consistent with other places which handle
exceptions in this file

https://codereview.chromium.org/1448223004/diff/40001/build/android/gyp/emma_...
build/android/gyp/emma_instr.py:197: options.src_root)
I am confused. There is an '_' before the 'C" in _CreateSourcesListFile()

[agrieve, 2015-11-18 16:06:18]

https://codereview.chromium.org/1448223004/diff/40001/build/android/gyp/emma_...
File build/android/gyp/emma_instr.py (right):

https://codereview.chromium.org/1448223004/diff/40001/build/android/gyp/emma_...
build/android/gyp/emma_instr.py:116: source_dirs = set()
On 2015/11/18 15:59:28, pkotwicz wrote:
> It might be because I am relatively new to Python, but I find Python shorthand
> to hard to read

In general, List comprehensions are preferred when applicable. Feel free to
leave this on multiple lines, but the really-should-do part is replacing the for
loop with 

source_dirs = set(os.path.dirname(p) for p in source_files)

[pkotwicz, 2015-11-18 17:02:59]

The CQ bit was checked by pkotwicz@chromium.org

[pkotwicz, 2015-11-18 17:02:59]

The patchset sent to the CQ was uploaded after l-g-t-m from agrieve@chromium.org
Link to the patchset: https://codereview.chromium.org/1448223004/#ps60001
(title: " ")

[pkotwicz, 2015-11-18 17:03:02]

https://codereview.chromium.org/1448223004/diff/40001/build/android/gyp/emma_...
File build/android/gyp/emma_instr.py (right):

https://codereview.chromium.org/1448223004/diff/40001/build/android/gyp/emma_...
build/android/gyp/emma_instr.py:116: source_dirs = set()
According to the Google style guide, "List comprehensions are Okay to use for
simple cases.". I guess this is a "simple case"
Fixed!

[commit-bot: I haz the power, 2015-11-18 17:05:46]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1448223004/60001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1448223004/60001

[commit-bot: I haz the power, 2015-11-18 18:54:08]

Committed patchset #3 (id:60001)

[commit-bot: I haz the power, 2015-11-18 18:55:23]

Patchset 3 (id:??) landed as
https://crrev.com/17ec244eb92d303b49b3f89eace52ac38d3698d5
Cr-Commit-Position: refs/heads/master@{#360376}