Allow mojo_debug gdb attach to search symbols in multiple directories.

mojo/devtools/common/mojo_debug

Index: mojo/devtools/common/mojo_debug
diff --git a/mojo/devtools/common/mojo_debug b/mojo/devtools/common/mojo_debug
index cc1aa0b060f39f954cf999b6fb3d3cd59700dba3..5c0e662937fa6a234278d6d82f95b010c3df2e7b 100755
--- a/mojo/devtools/common/mojo_debug
+++ b/mojo/devtools/common/mojo_debug
@@ -222,12 +222,12 @@ def _gdb_attach(args):
                                         'android_gdb', 'session.py')
   debug_session_arguments = {}
   if args.build_dir:
-    debug_session_arguments["build_directory"] = args.build_dir
+    debug_session_arguments["build_directory_list"] = args.build_dir
   else:
     try:
-      debug_session_arguments["build_directory"] = os.path.join(
+      debug_session_arguments["build_directory_list"] = os.path.join(
           _get_dir_above('out'), 'out', 'android_Debug')
-      if not os.path.exists(debug_session_arguments["build_directory"]):
+      if not os.path.exists(debug_session_arguments["build_directory_list"]):
         raise DirectoryNotFoundException()
     except DirectoryNotFoundException:
       logging.fatal("Unable to find the build directory, please specify it "
@@ -308,7 +308,7 @@ def _add_gdb_command(subparsers):
   gdb_attach_parser.add_argument('--ndk-dir', type=str,
       help='path to the directory containing the Android NDK')
   gdb_attach_parser.add_argument('--build-dir', type=str,
-      help='path to the build directory')
+      help='List of paths to build directories, separated by commas')

[qsr (NOT THE RIGHT qsr), 2015/09/03 10:34:04]

Do you think it is better to do it this way, instead of allowing to set this
argument multiple times?

[etiennej, 2015/09/03 11:45:44]

Good point. I also changed the device stack command that I modified in a similar
way earlier.

   gdb_attach_parser.add_argument('--pyelftools-dir', type=str,
       help='Path to a directory containing third party libraries')
   gdb_attach_parser.add_argument('--gsutil-dir', type=str,