Add mb config for CrWinClang64(dbg).

tools/mb/mb_config.pyl

Index: tools/mb/mb_config.pyl
diff --git a/tools/mb/mb_config.pyl b/tools/mb/mb_config.pyl
index 1ec74f9a3c0d8eac1042768e78c9118f8188c2f5..52556bf1f90583f5a7ce4e259d7fa0903eb856bf 100644
--- a/tools/mb/mb_config.pyl
+++ b/tools/mb/mb_config.pyl
@@ -30,6 +30,8 @@
     'gn_debug_static_bot': ['gn', 'debug_static_bot'],
     'gn_debug_static_bot_x86': ['gn', 'debug_static_bot', 'x86'],
     'gyp_release_bot': ['gyp', 'release_bot'],
+    'win_clang_debug_bot':
+        ['gn', 'clang', 'debug', 'shared', 'minimal_symbols'],

[Dirk Pranke, 2015/06/09 01:14:52]

The style rules for this file aren't set in stone, but you can see I'm trying to
usually include "gyp" or "gn" in the name of the config, so that you can see at
a glance down in the bot mappings whether a given bot is using gyp or gn. I also
tend to leave out the platform if possible"

So, I might refactor this a bit as:

"gn_clang_debug_bot": ['gn', 'clang', 'debug_bot']

(shared and minimal symbols are mixed in automatically w/ debug_bot).

[Nico, 2015/06/09 01:19:24]

debug_bot also enables goma from what I understand (?), and goma doesn't work
with clang/win yet.

   },
   
   # This is a list of configs that do not actually exist on any bot
@@ -68,6 +70,11 @@
       'gyp_defines': 'chromeos=1',
     },
 
+    'clang': {
+      'gn_args': 'is_clang=true',
+      'gyp_defines': 'clang=1',
+    },
+
     'dcheck_always_on': {
       'gn_args': 'dcheck_always_on=true',
       'gyp_defines': 'dcheck_always_on=1',
@@ -167,6 +174,9 @@
       'Linux GN': 'gn_release_bot',
       'Linux GN (dbg)': 'gn_debug_bot'
     },
+    'chromium.fyi': {
+      'CrWinClang64(dbg)': 'win_clang_debug_bot',
+    },

[Dirk Pranke, 2015/06/09 01:14:52]

and then rename this to just 'gn_clang_debug_bot'.

     'chromium.webrtc.fyi': {
       'Android GN': 'android_gn_release_bot',
       'Android GN (dbg)': 'android_gn_debug_bot',