recipes: Add a GN flavor.

infra/bots/recipe_modules/skia/gn_flavor.py

+# Copyright 2016 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.
+
+import default_flavor
+
+"""GN flavor utils, used for building Skia with GN."""
+
+class GNFlavorUtils(default_flavor.DefaultFlavorUtils):
+  def compile(self, target):
+    """Build Skia with GN."""
+    # Get the gn executable.
+    fetch_gn= self._skia_api.skia_dir.join('bin', 'fetch_gn')
+    self._skia_api.run(self._skia_api.m.step, 'fetch-gn', cmd=[fetch_gn],
+                       cwd=self._skia_api.m.path['checkout'])

[borenet, 2016/07/27 19:51:37]

Prefer cwd=self._skia_api.skia_dir here and below.

[jcgregorio, 2016/07/27 20:01:01]

Done.

+
+    is_debug = 'is_debug=' + (
+            'true' if self.configuration == 'Debug' else 'false'

[borenet, 2016/07/27 19:51:37]

Does self.configuration exist?  It might need to be
self._skia_api.configuration.

[jcgregorio, 2016/07/27 20:01:01]

Done.

+            )

[borenet, 2016/07/27 19:51:37]

Indent?

[jcgregorio, 2016/07/27 20:01:01]

Did in a different way.

+    gn_args = [is_debug]
+    out_dir = 'out/%d' % self.configuration
+    # Run gn gen out/BUILDTYPE --args="is_debug=true"
+    gn_gen = ['gn', 'gen', out_dir, '--args=%s' % ' '.join(gn_args)]

[borenet, 2016/07/27 19:51:37]

It may not matter yet, but if it's "gn.exe" on windows this will need to pick
the right thing based on the builder platform.

[jcgregorio, 2016/07/27 20:01:01]

Fixed.

+    self._skia_api.run(self._skia_api.m.step, 'gn_gen', cmd=gn_gen,
+                       cwd=self._skia_api.m.path['checkout'])
+
+    # Run ninja
+    ninja_cmd = ['ninja', '-C', out_dir, 'skia'],
+    self._skia_api.run(self._skia_api.m.step, 'compile %s' % target,
+            cmd=ninja_cmd,
+            cwd=self._skia_api.m.path['checkout'])