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

scripts/slave/recipes/chromium_trybot.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.
 
 DEPS = [
   'chromium',
   'gclient',
   'itertools',
   'json',
   'path',
@@ skipping 250 matching lines @@
       if api.step_history.last_step().retcode != 0:
         yield (
           api.path.rmcontents('slave build directory', api.path['slave_build']),
           api.gclient.checkout(),
           api.rietveld.apply_issue(),
           api.chromium.runhooks(),
         )
   else:
     yield api.chromium.runhooks()
 
+  # TODO(dpranke): crbug.com/353690. Remove the gn-specific steps from this
+  # recipe and stand up a dedicated GN bot when the GN steps take up enough
+  # resources to be worth it. For now, we run GN and generate files into a new
+  # Debug_gn / Release_gn dir, and then run a compile in that dir.
+  gn_output_dir = api.path['slave_build'].join(api.chromium.c.BUILD_CONFIG +
+                                               '_gn')
+  should_run_gn = api.properties.get('buildername') in ('linux_chromium',
+                                                        'linux_chromium_rel')
+
   test_spec = api.step_history['read test spec'].json.output
   test_spec = [s.encode('utf-8') for s in test_spec]
 
   tests = []
   tests.append(CheckdepsTest())
   tests.append(Deps2GitTest())
   for name in GTEST_TESTS + test_spec:
     tests.append(GTestTest(name))
   tests.append(NaclIntegrationTest())
 
   compile_targets = list(api.itertools.chain(
                              *[t.compile_targets() for t in tests]))
   yield api.chromium.compile(compile_targets,
                              name='compile (with patch)',
                              abort_on_failure=False,
                              can_fail_build=False)
-  if api.step_history['compile (with patch)'].retcode != 0:
+  if should_run_gn:
+    yield api.chromium.run_gn(gn_output_dir)
+    yield api.chromium.compile_with_ninja('compile (gn with patch)',
+                                          gn_output_dir)
+
+  if ((api.step_history['compile (with patch)'].retcode != 0) or
+      (should_run_gn and
+       api.step_history['compile (gn with patch)'].retcode != 0)):
     # Only use LKCR when compile fails. Note that requested specific revision
     # can still override this.
     api.gclient.set_config('chromium_lkcr')
 
     # Since we're likely to switch to an earlier revision, revert the patch,
     # sync with the new config, and apply issue again.
     yield api.gclient.checkout(revert=True)
     yield api.rietveld.apply_issue()
 
     # TODO(phajdan.jr): Extend to all platforms, http://crbug.com/354731 .
@@ skipping 11 matching lines @@
           api.chromium.runhooks(),
           api.chromium.compile(compile_targets,
                                name='compile (with patch, lkcr, clobber, nuke)',
                                force_clobber=True)
         )
     else:
       yield api.chromium.compile(compile_targets,
                                  name='compile (with patch, lkcr, clobber)',
                                  force_clobber=True)
 
+    if should_run_gn:
+      yield api.path.rmcontents('slave gn build directory', gn_output_dir)
+      yield api.chromium.run_gn(gn_output_dir)
+      yield api.chromium.compile_with_ninja(
+          'compile (gn with patch, lkcr, clobber)', gn_output_dir)
+
   # Do not run tests if the build is already in a failed state.
   if api.step_history.failed:
     return
 
   if recipe_config['compile_only']:
     return
 
-  # TODO(phajdan.jr): Make it possible to retry telemtry tests (add JSON).
+  # TODO(dpranke): crbug.com/353690. It would be good to run gn_unittests
+  # out of the gn build dir, but we can't use runtest()
+  # because of the different output directory; this means
+  # we don't get annotations and don't get retry of the tests for free :( .
+
+  # TODO(phajdan.jr): Make it possible to retry telemetry tests (add JSON).
   yield (
     api.chromium.run_telemetry_unittests(),
     api.chromium.run_telemetry_perf_unittests(),
   )
 
   def deapply_patch_fn(failing_tests):
     yield (
       api.gclient.revert(),
       api.chromium.runhooks(),
     )
@@ skipping 115 matching lines @@
   )
 
   yield (
     api.test('compile_failure_linux') +
     props() +
     api.platform.name('linux') +
     api.step_data('compile (with patch)', retcode=1) +
     api.step_data('compile (with patch, lkcr, clobber)', retcode=1) +
     api.step_data('compile (with patch, lkcr, clobber, nuke)', retcode=1)
   )
+
+  # TODO(dpranke): crbug.com/353690.
+  # Remove this when we make GN a standalone recipe.
+  yield (
+    api.test('unittest_should_run_gn') +
+    api.properties.tryserver(buildername='linux_chromium',
+                             build_config='Debug') +
+    api.platform.name('linux') +
+    api.step_data('compile (gn with patch)')
+  )
+
+  yield (
+    api.test('unittest_should_run_gn_compile_failure') +
+    api.properties.tryserver(buildername='linux_chromium',
+                             build_config='Debug') +
+    api.platform.name('linux') +
+    api.step_data('compile (gn with patch)', retcode=1)
+  )