Add GN (the build tool) to the chromium.linux buildbots and try jobs

scripts/slave/recipe_modules/chromium/api.py

 # Copyright 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 from slave import recipe_api
 from slave import recipe_util
 
 
 class TestLauncherFilterFileInputPlaceholder(recipe_util.Placeholder):
   def __init__(self, api, tests):
@@ skipping 212 matching lines @@
   def run_telemetry_perf_unittests(self):
     return self.runtest(
         self.m.path['checkout'].join('tools', 'perf', 'run_tests'),
         args=['--browser=%s' % self.c.BUILD_CONFIG.lower()],
         annotate='gtest',
         name='telemetry_perf_unittests',
         test_type='telemetry_perf_unittests',
         python_mode=True,
         xvfb=True)
 
-  def runhooks(self, **kwargs):
+  def runhooks(self, run_gyp=True, **kwargs):
     """Run the build-configuration hooks for chromium."""
     env = kwargs.get('env', {})
-    env.update(self.c.gyp_env.as_jsonish())
+    if run_gyp:
+      env.update(self.c.gyp_env.as_jsonish())
+    else:
+      env['GYP_CHROMIUM_NO_ACTION'] = 1
     kwargs['env'] = env
     return self.m.gclient.runhooks(**kwargs)
 
+  def compile_with_ninja(self, name, output_dir):
+    ninja_path = self.m.path['depot_tools'].join('ninja',
+                                                 platform_ext={'win': '.exe'})
+    return self.m.step(name=name, cmd=[ninja_path, '-C', output_dir])
+
+  def run_gn(self, output_dir):
+    config = self.c.BUILD_CONFIG
+    gn_wrapper_script_path = self.m.path['depot_tools'].join('gn.py')
+    gn_build_config_specific_args = {
+        'Debug': ['--args=is_debug=true'],
+        'Release': ['--args=is_debug=false'],
+    }
+    gn_args = ['gen', '-o', output_dir] + gn_build_config_specific_args[config]
+    return self.m.python('gn', gn_wrapper_script_path, args=gn_args)
+
   def taskkill(self):
     return self.m.python(
       'taskkill',
       self.m.path['build'].join('scripts', 'slave', 'kill_processes.py'))
 
   def cleanup_temp(self):
     return self.m.python(
       'cleanup_temp',
       self.m.path['build'].join('scripts', 'slave', 'cleanup_temp.py'))
 
@@ skipping 48 matching lines @@
               '--json', self.m.json.output()],
         step_test_data=lambda: self.m.json.test_api.output([]),
         **kwargs)
 
   def deps2submodules(self, **kwargs):
     return self.m.python(
         'deps2submodules',
         self.m.path['checkout'].join('tools', 'deps2git', 'deps2submodules.py'),
         args=['--gitless', self.m.path['checkout'].join('.DEPS.git')],
         **kwargs)