Add a "dump-json" generator that dumps the dependency graph.

Add a "dump-json" generator that dumps the dependency graph.

- Add a generator-specific variable to turn off the automatic
  flattening of static library dependencies.
- Add a new simple generator module that just dumps the graph as
  JSON.

[Evan Martin, 2011-05-24 21:20:44]

Initially I put all this graphviz code in here, but then after looking at some
graphs with Tony he started asking me about alternative visualizations etc.  So
I instead reduced it to this minimal general intrusion onto gyp; everything
beyond this we can do in a separate script that post-processes.

See e.g. http://www.corp.google.com/~evanm/projects/chrome/gyp/browse.html for a
demo of using the output.

[Mark Mentovai, 2011-05-24 21:46:15]

LG otherwise

http://codereview.chromium.org/7067039/diff/1/pylib/gyp/__init__.py
File pylib/gyp/__init__.py (right):

http://codereview.chromium.org/7067039/diff/1/pylib/gyp/__init__.py#newcode80
pylib/gyp/__init__.py:80: 'generator_wants_flattened_static_libraries':
“flattened” is a bad name because it means something else over in input.py,
where this is used.

generator_wants_static_library_dependencies_adjusted would be most accurate
using the terminology over there, if you don’t think it’s too long.

http://codereview.chromium.org/7067039/diff/1/pylib/gyp/generator/dump-json.py
File pylib/gyp/generator/dump-json.py (right):

http://codereview.chromium.org/7067039/diff/1/pylib/gyp/generator/dump-json.p...
pylib/gyp/generator/dump-json.py:39: # Queue of targets we've yet to visit.
You know how I feel about “we” in comments.

[Nico, 2011-05-25 01:57:20]

I have a patch that adds a json output generator as well (for a completely
different cause). Maybe this one could be called dump-dependency-json, since
json is such a generic term?

[Evan Martin, 2011-05-25 02:29:16]

On 2011/05/25 01:57:20, Nico wrote:
> I have a patch that adds a json output generator as well (for a completely
> different cause). Maybe this one could be called dump-dependency-json, since
> json is such a generic term?

Ack, sorry!  I will rename it (I already committed it, not sure why it didnt'
close)