Fix check for MojoShell.apk

sky/tools/skydb

 #!/usr/bin/env python
 # 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.
 
 from skypy.skyserver import SkyServer
 import argparse
 import json
 import logging
 import os
@@ skipping 157 matching lines @@
         pm_command = [ADB_PATH, 'shell', 'pm', 'path', package]
         pm_output = subprocess.check_output(pm_command)
         # e.g. package:/data/app/org.chromium.mojo.shell-1/base.apk
         return pm_output.split(':')[-1]
 
     def start_command(self, args):
         # FIXME: Lame that we use self for a command-specific variable.
         self.paths = self._create_paths_for_build_dir(args.build_dir)
         self.stop_command(None) # Quit any existing process.
 
-        if not os.path.exists(self.paths.mojo_shell_path):
-            print "mojo_shell not found in build_dir '%s'" % args.build_dir
-            print "Are you sure you sure that's a valid build_dir location?"
-            print "See skydb start --help for more info"
-            sys.exit(2)
-
         # FIXME: This is probably not the right way to compute is_android
         # from the build directory?
         gn_args = gn_args_from_build_dir(self.paths.build_dir)
         is_android = 'android_sdk_version' in gn_args
 
+        shell_found = True
+        if is_android:
+            apk_path = os.path.join(self.paths.build_dir, 'apks', ANDROID_APK_NAME)
+            if not os.path.exists(apk_path):
+                print "%s not found in build_dir '%s'" % \
+                    (ANDROID_APK_NAME, os.path.join(args.build_dir, 'apks'))
+                shell_found = False
+        elif not os.path.exists(self.paths.mojo_shell_path):
+            print "mojo_shell not found in build_dir '%s'" % args.build_dir
+            shell_found = False
+
+        if not shell_found:
+            print "Are you sure you sure that's a valid build_dir location?"
+            print "See skydb start --help for more info"
+            sys.exit(2)
+
         if is_android and args.gdb and not 'is_debug' in gn_args:
             # FIXME: We don't include gdbserver in the release APK...
             print "Cannot debug Release builds on Android"
             sys.exit(2)
 
         sdk_root = os.path.join(self.paths.build_dir, 'gen', 'sky_sdk')
         packages_root = os.path.join(sdk_root, 'packages_root')
         subprocess.check_call([
             os.path.join(self.paths.sky_tools_directory, 'deploy_sdk.py'),
             '--build-dir', self.paths.build_dir,
@@ skipping 10 matching lines @@
 
         self.pids['build_dir'] = self.paths.build_dir
         self.pids['sky_command_port'] = args.command_port
 
         if is_android:
             # TODO(eseidel): This should move into a helper method and handle
             # failures with nice messages explaining how to get root.
             subprocess.check_call([ADB_PATH, 'root'])
 
             # We could make installing conditional on an argument.
-            apk_path = os.path.join(self.paths.build_dir, 'apks',
-                ANDROID_APK_NAME)
             subprocess.check_call([ADB_PATH, 'install', '-r', apk_path])
 
             port_string = 'tcp:%s' % sky_server.port
             subprocess.check_call([
                 ADB_PATH, 'reverse', port_string, port_string
             ])
             self.pids['remote_sky_server_port'] = sky_server.port
 
             port_string = 'tcp:%s' % args.command_port
             subprocess.check_call([
@@ skipping 385 matching lines @@
         load_parser.set_defaults(func=self.load_command)
 
         args = parser.parse_args()
         args.func(args)
 
         self._write_pid_file(PID_FILE_PATH, self.pids)
 
 
 if __name__ == '__main__':
     SkyDebugger().main()