headless: Initial headless embedder API implementation

BUILD.gn

 # Copyright (c) 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.
 
 # This is the root build file for GN. GN will start processing by loading this
 # file, and recursively load all dependencies until all dependencies are either
 # resolved or known not to exist (which will cause the build to fail). So if
 # you add a new build file, there must be some path of dependencies from this
 # file to your new one or GN won't know about it.
 
@@ skipping 723 matching lines @@
     }
   }
 
   if (is_android) {
     deps += [
       "//build/android/gyp/test:hello_world",
       "//build/android/incremental_install:bootstrap_java",
     ]
   }
 
+  if (is_linux && use_ozone) {
+    deps += [
+      "//headless",
+      "//headless:headless_tests",
+    ]
+  }
+
   if (!is_chromecast && (is_android || is_linux || is_chromeos)) {
     deps += [
       "//blimp",
       "//blimp:blimp_tests",
     ]
   }
 }
 
 group("gn_mojo_targets") {
   testonly = true
@@ skipping 125 matching lines @@
       ]
 
       if (target_cpu == "x86") {
         deps += [ "//chrome/tools/crash_service:crash_service_win64" ]
       }
     } else {
       deps += [ "//breakpad:minidump_stackwalk($host_toolchain)" ]
     }
   }
 }