bluetooth: Create bluetooth_metrics_hash tool.

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 590 matching lines @@
     ]
   }
 }
 
 group("gn_only") {
   testonly = true
 
   deps = []
 
   if (!is_ios) {
-    deps += [ "//mojo/common:mojo_common_perftests" ]
+    deps += [
+      "//content/browser/bluetooth/tools:bluetooth_metrics_hash",

[Dirk Pranke, 2016/04/15 22:57:10]

this'll result in building an android executable on android; is that your
intent?

[scheib, 2016/04/15 23:04:43]

No, but my intent is to keep the tool and config as simple as possible. 

I attempted adding ($host_toolchain), similar to imagediff, however that caused
non-obvious tool chain errors on both the android and chrome_os build configs I
have setup. If you'd like to help sort those out to make it easier for future
tools to cut'n'paste correct setup I'm happy to do it.

Else, if we just want to keep it simple I suppose I should create a new if
(!is_android && !is_ios) section.

+      "//mojo/common:mojo_common_perftests",
+    ]
   }
 
   if (!is_android && !is_ios && !is_chromeos) {
     deps += [ "//components/proximity_auth:proximity_auth_unittests" ]
   }
 
   if (is_win || is_linux) {
     deps += [
       ":mojo_apptests",
       "//components/mus/demo",
@@ skipping 279 matching lines @@
   assert(target_name != "")  # Mark as used.
   sources = invoker.actual_sources
   assert(
       sources == invoker.actual_sources,
       "Do not use a platform name in your output directory (found \"$root_build_dir\"). http://crbug.com/548283")
 }
 
 assert_valid_out_dir("_unused") {
   actual_sources = [ "$root_build_dir/foo" ]
 }