Add enable_vr_shell build time flag and show icon in Daydream app luncher

chrome/android/BUILD.gn

 # Copyright 2014 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("//build/config/android/config.gni")
 import("//build/config/android/rules.gni")
 import("//build_overrides/v8.gni")
 import("//chrome/android/chrome_public_apk_tmpl.gni")
 import("//chrome/common/features.gni")
 import("//chrome/version.gni")
@@ skipping 28 matching lines @@
 
 # GYP: //chrome/android/chrome_apk.gyp:chrome_apk_manifest
 jinja_template("chrome_public_apk_manifest") {
   input = "java/AndroidManifest.xml"
   output = "$root_gen_dir/chrome_public_apk_manifest/AndroidManifest.xml"
   variables = chrome_public_jinja_variables
   variables += [
     "min_sdk_version=16",
     "target_sdk_version=23",
   ]
+  if (enable_vr_shell) {
+    variables += [ "enable_vr_shell=1" ]
+  }
 }
 
 # GYP: //chrome/android/chrome_apk.gyp:chrome_sync_shell_apk_manifest
 jinja_template("chrome_sync_shell_apk_manifest") {
   input = "java/AndroidManifest.xml"
   output = "$root_gen_dir/chrome_sync_shell_apk_manifest/AndroidManifest.xml"
   variables = chrome_sync_shell_jinja_variables
   variables += [
     "min_sdk_version=16",
     "target_sdk_version=22",
@@ skipping 558 matching lines @@
     apk_name = "ChromeSyncShellTest"
     apk_under_test = ":chrome_sync_shell_apk"
     android_manifest = chrome_sync_shell_test_apk_manifest
     android_manifest_dep = ":chrome_sync_shell_test_apk_manifest"
     deps = [
       ":chrome_sync_shell_test_apk_java",
     ]
     proguard_enabled = !is_java_debug
   }
 }