Reland "Add debug chromium bots"

This is a reland of 2db4180229db1c343018f96400d97944534b7a77

This CL will not schedule builds on the bots initially. This will let
me test what's going wrong without breaking the waterfall and confusing
sheriffs.

Original change's description:
> Add debug chromium bots
>
> These are mirrors of the existing release bots
>
> Bug: 867725
> Change-Id: I6f59d04a82103572e801273e294534e822d3e03d
> Reviewed-on: https://chromium-review.googlesource.com/1159172
> Commit-Queue: Stephen Martinis <[email protected]>
> Reviewed-by: Nodir Turakulov <[email protected]>
> Reviewed-by: Dirk Pranke <[email protected]>
> Reviewed-by: Kenneth Russell <[email protected]>
> Cr-Commit-Position: refs/heads/master@{#582390}

Bug: 867725
Change-Id: Ic401e310241bb986f3fbba4666e2e9bfa191be5a
Reviewed-on: https://chromium-review.googlesource.com/1184120
Commit-Queue: Stephen Martinis <[email protected]>
Reviewed-by: John Budorick <[email protected]>
Reviewed-by: Kenneth Russell <[email protected]>
Cr-Commit-Position: refs/heads/master@{#585600}
diff --git a/testing/buildbot/test_suite_exceptions.pyl b/testing/buildbot/test_suite_exceptions.pyl
index 579e19b..3442ef3 100644
--- a/testing/buildbot/test_suite_exceptions.pyl
+++ b/testing/buildbot/test_suite_exceptions.pyl
@@ -255,7 +255,9 @@
   },
   'checkbins': {
     'remove_from': [
+      'linux-dbg',
       'linux-rel',
+      'mac-dbg',
       'mac-rel',
     ],
   },
@@ -986,16 +988,28 @@
   },
   'sizes': {
     'remove_from': [
+      'win32-dbg',
       'win32-rel',
+      'win-dbg',
       'win-rel',
     ],
     'modifications': {
       # chromium
+      'mac-dbg': {
+        'args': [
+          'mac-debug/sizes',
+        ],
+      },
       'mac-rel': {
         'args': [
           'mac-release/sizes',
         ],
       },
+      'linux-dbg': {
+        'args': [
+          'linux-debug-64/sizes',
+        ],
+      },
       'linux-rel': {
         'args': [
           'linux-release-64/sizes',