add gn_android_flavor

infra/bots/recipe_modules/flavor/gn_android_flavor.py

Index: infra/bots/recipe_modules/flavor/gn_android_flavor.py
diff --git a/infra/bots/recipe_modules/flavor/gn_android_flavor.py b/infra/bots/recipe_modules/flavor/gn_android_flavor.py
new file mode 100644
index 0000000000000000000000000000000000000000..8965233e06ef0c9f0f9d8e427978cd91e6b29a67
--- /dev/null
+++ b/infra/bots/recipe_modules/flavor/gn_android_flavor.py
@@ -0,0 +1,40 @@
+# 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 Android flavor utils, used for building Skia for Android with GN."""
+class GNAndroidFlavorUtils(default_flavor.DefaultFlavorUtils):
+  def supported(self):
+    return 'GN_Android' == self.m.vars.builder_cfg.get('extra_config', '')
+
+  def compile(self, unused_target, **kwargs):
+    compiler      = self.m.vars.builder_cfg.get('compiler')
+    configuration = self.m.vars.builder_cfg.get('configuration')
+    os            = self.m.vars.builder_cfg.get('os')
+    target_arch   = self.m.vars.builder_cfg.get('target_arch')
+
+    assert compiler == 'Clang'  # At this rate we might not ever support GCC.
+
+    compiler_prefix = ''
+    ccache = self.m.run.ccache()
+    if ccache:
+      compiler_prefix = ccache
+
+    ndk_asset = 'android_ndk_linux' if os == 'Ubuntu' else 'android_ndk_darwin'
+
+    quote = lambda x: '"%s"' % x
+    gn_args = ' '.join('%s=%s' % (k,v) for (k,v) in {
+        'compiler_prefix': quote(compiler_prefix),
+        'is_debug': 'true' if configuration == 'Debug' else 'false',
+        'ndk': quote(self.m.vars.slave_dir.join(ndk_asset)),
+        'target_cpu': quote(target_arch),
+    }.iteritems())
+
+    run = lambda title, cmd: self.m.run(self.m.step, title, cmd=cmd,
+                                        cwd=self.m.vars.skia_dir, **kwargs)
+
+    run('fetch-gn', [self.m.vars.skia_dir.join('bin', 'fetch-gn')])
+    run('gn gen', ['gn', 'gen', self.out_dir, '--args=' + gn_args])
+    run('ninja', ['ninja', '-C', self.out_dir])