Set product_name on many targets to use a crashpad_ prefix

Set target_name on many targets to use a crashpad_ prefix.

In Chromium, many targets are built, sharing a single output directory.
Collisions are likely. When integrating Crashpad into Chromium, the
ui/snapshot library and Crashpad’s snapshot library were found to
conflict.

This change gives most Crashpad targets a “crashpad_” prefix to avoid
conflicts. All library and test targets are given a target_name with
this prefix. Existing tools are not likely to conflict with anything
else and are not given a prefix.

BUG=crashpad:12
R=rsesek@chromium.org, scottmg@chromium.org

Committed: https://chromium.googlesource.com/crashpad/crashpad/+/b256df05344dd0593079d72ad0174f218c4592f8

[Mark Mentovai, 2015-03-07 19:22:59]

mark@chromium.org changed reviewers:
+ rsesek@chromium.org

[Mark Mentovai, 2015-03-07 19:32:26]

mark@chromium.org changed reviewers:
+ scottmg@chromium.org

[scottmg, 2015-03-07 21:33:03]

I might have just changed the target_names? But lgtm.

[Mark Mentovai, 2015-03-07 21:51:14]

If you guys would prefer that, I can do it that way. The real reason I did it
with product_name was to keep the changes from bubbling out to the dependencies
sections.

[Robert Sesek, 2015-03-08 03:41:34]

I don't have a philosophical opinion on whether the target_name should match
product_name, and I understand the desire to not have the rename spill out to
dependencies, but usually consistency is a good thing. How does this affect the
build? Can I do:

$ ninja -C out/Debug crashpad_client_test
$ ./out/Debug/crashpad_client_test

Or will I still have to build target client_test and then know to use executable
crashpad_client_test?

[Mark Mentovai, 2015-03-08 15:22:05]

ninja responds to both names:

mark@mela zsh% ninja -C out/Debug client_test         
ninja: Entering directory `out/Debug'
ninja: no work to do.
mark@mela zsh% ninja -C out/Debug crashpad_client_test
ninja: Entering directory `out/Debug'
ninja: no work to do.
mark@mela zsh% ninja -C out/Debug not_a_real_name     
ninja: Entering directory `out/Debug'
ninja: error: unknown target 'not_a_real_name'

But, on reflection, it’s a little confusing to have to depend on client_test and
execute crashpad_client_test.

I updated this to just use target_name, and bit the bullet and changed the
dependencies.

[Robert Sesek, 2015-03-08 19:58:12]

Yeah, I thought ninja allowed both, but I do think the consistency is better.
LGTM

[Mark Mentovai, 2015-03-08 20:25:48]

Committed patchset #3 (id:40001) manually as
b256df05344dd0593079d72ad0174f218c4592f8 (presubmit successful).