Add mb config for chromium.chromedriver.

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 628f64337322d94691a050f44b4054583bf85563..0aeca316f3f69fe8d855e8cef375a8681519c410 100644
--- a/tools/mb/mb_config.pyl
+++ b/tools/mb/mb_config.pyl
@@ -69,6 +69,13 @@
       'Google Chrome Win': 'gn_official_goma_minimal_symbols_x86',
     },
 
+    'chromium.chromedriver': {
+      'Win7': 'gn_release_bot_x86',
+      'Mac 10.6': 'gn_release_bot',
+      'Linux': 'gn_release_bot',
+      'Linux32': 'gn_release_bot_x86',

[Dirk Pranke, 2016/07/22 03:11:46]

Do you need Linux 32? We don't support Chrome on Linux 32 anymore ...

[samuong, 2016/07/22 03:46:27]

We still have a linux32 bot, which tests chromedriver against 32-bit chromium
builds. It'll probably go away one day, but in the meantime it's still there, so
it needs to be configured.

+    },
+
     'chromium.chromiumos': {
       'ChromiumOS amd64-generic Compile': 'cros_chrome_sdk_gn',
       'ChromiumOS daisy Compile': 'cros_chrome_sdk_gn',