WebRTC: Add Linux GCC bot.

scripts/slave/recipe_modules/chromium/config.py

Index: scripts/slave/recipe_modules/chromium/config.py
diff --git a/scripts/slave/recipe_modules/chromium/config.py b/scripts/slave/recipe_modules/chromium/config.py
index 61ba8d546faec2a358181f8f16f1c003b2ebbce9..d1d9933908cc6d8f4fd12bd83b71c54abce78bbf 100644
--- a/scripts/slave/recipe_modules/chromium/config.py
+++ b/scripts/slave/recipe_modules/chromium/config.py
@@ -282,6 +282,10 @@ def _clang_common(c):
 def clang(c):
   _clang_common(c)
 
+@config_ctx()

[Michael Achenbach, 2015/10/20 06:54:18]

If you put it into this file, maybe add group='compiler' for consistency
reasons? We never added group constraints in v8 - they always gave us trouble
when inheriting things that already had group constraints - so I'm not sure if
it's going to work.

[kjellander_chromium, 2015/10/20 07:43:23]

I tried but then it failed with:
BadConf: "no_clang" is a member of group "compiler", but ('default_compiler',)
already ran
using the current setup of configs.
I updated this in PS#3 and added Pawel to leave his opinion on how we should do.
I could also add a chromium_gcc config, but I'm not sure it makes sense since
there's no Chromium GCC bot.

+def no_clang(c):
+  c.gyp_env.GYP_DEFINES['clang'] = 0
+
 @config_ctx(group='compiler')
 def default_compiler(c):
   if c.TARGET_PLATFORM in ('mac', 'ios'):