Fix check for MojoShell.apk

sky/tools/skydb

Index: sky/tools/skydb
diff --git a/sky/tools/skydb b/sky/tools/skydb
index 8ef14abf07f43dc834d5250f5766eac699381c19..a2696bbdda356533d94a8e9179b46eb96433322f 100755
--- a/sky/tools/skydb
+++ b/sky/tools/skydb
@@ -175,17 +175,26 @@ class SkyDebugger(object):
         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
 
+        if is_android:

[eseidel, 2015/04/21 17:18:28]

I would have moved this into a helper function and made the path-computation
conditionalized on the if and shared the print/exit block.

Then the outer caller just looks like:

if not self._validate_build_dir(self.paths.build_dir, is_android):
   sys.exit(2)

def _validate_build_dir(self, build_dir, is_android):
   if is_android:
      apk_path...
      executable_path = ...
   else:
      executable_path = ...
   if os.path.exists(mojo_shell_path):
      return True
   print "%s not found in %s % (os.path.basename(executable_path),
os.path.dirname(executable_path))
   ....
   return false.

+          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'))
+            print "Are you sure you sure that's a valid build_dir location?"
+            print "See skydb start --help for more info"
+            sys.exit(2)
+        elif 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)
+
         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"
@@ -216,8 +225,6 @@ class SkyDebugger(object):
             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