Specifying 'ninja' build tool for Android builds.
Specifying 'ninja' build tool for Android builds.

BUG=142465


Review URL: https://chromiumcodereview.appspot.com/10893010

git-svn-id: 239fca9b83025a0b6f823aeeca02ba5be3d9fd76@153986 0039d316-1c4b-4281-b951-d872f2087c98

eunchong/build,eunchong/build,eunchong/build,eunchong/build