[testing] remove unnecessary exceptions config

I think it is sufficient to specify dimensions_sets only in builders
config.
No behavior change intended.

Change-Id: I36c50d22f5d5b56f49d54c838848eb59565b7a00
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1735451
Commit-Queue: Ben Pastene <bpastene@chromium.org>
Reviewed-by: Ben Pastene <bpastene@chromium.org>
Auto-Submit: Takuto Ikuta <tikuta@chromium.org>
Cr-Commit-Position: refs/heads/master@{#684006}

testing/buildbot/test_suite_exceptions.pyl

@@ -1932,11 +1932,6 @@
           '--enable-sanitizer',
         ],
         'swarming': {
-          'dimension_sets': [
-            {
-              'os': 'Ubuntu-16.04',
-            },
-          ],
           'shards': 20,
         },
       },
@@ -1949,11 +1944,6 @@
           '--enable-leak-detection',
         ],
         'swarming': {
-          'dimension_sets': [
-            {
-              'os': 'Ubuntu-16.04',
-            },
-          ],
           'shards': 10,
         },
       },
@@ -1966,26 +1956,12 @@
           '--enable-sanitizer',
         ],
         'swarming': {
-          'dimension_sets': [
-            {
-              'os': 'Ubuntu-16.04',
-            },
-          ],
           'expiration': 36000,
           'hard_timeout': 10800,
           'io_timeout': 3600,
           'shards': 20,
         },
       },
-      'WebKit Win10': {
-        'swarming': {
-          'dimension_sets': [
-            {
-              'os': 'Windows-10-15063',
-            },
-          ],
-        },
-      },
       # chromium.win
       'Win7 Tests (dbg)(1)': {
         'args': [

testing/buildbot/waterfalls.pyl

@@ -3974,6 +3974,9 @@
     'name': 'chromium.win',
     'machines': {
       'WebKit Win10': {
+        'mixins': [
+            'win10',
+        ],
         'test_suites': {
           'isolated_scripts': 'chromium_webkit_isolated_scripts',
         },