Revert "Enable {site_per_process_,}webkit_layout_tests on chromium.linux:Linux Tests (dbg)(1)."

This reverts commit 906757f0b18f19bfe517d9b78cb8e36d760e1401.

Reason for revert: Failing frequently & imposing nontrivial load on the linux pool.

Original change's description:
> Enable {site_per_process_,}webkit_layout_tests on chromium.linux:Linux Tests (dbg)(1).
> 
> Bug: 801478
> Change-Id: Ibf9251d0f5a9d301154c3fa0d76aa2d136618498
> Reviewed-on: https://chromium-review.googlesource.com/864622
> Commit-Queue: Dirk Pranke <[email protected]>
> Reviewed-by: Dirk Pranke <[email protected]>
> Cr-Commit-Position: refs/heads/master@{#529042}

[email protected],[email protected]

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: 801478
Change-Id: I7ae54209b64869ffcf3f03efe59f3e9b1ab26b87
Reviewed-on: https://chromium-review.googlesource.com/868493
Reviewed-by: John Budorick <[email protected]>
Reviewed-by: Dirk Pranke <[email protected]>
Commit-Queue: John Budorick <[email protected]>
Cr-Commit-Position: refs/heads/master@{#529789}
diff --git a/testing/buildbot/test_suite_exceptions.pyl b/testing/buildbot/test_suite_exceptions.pyl
index 78ad7a9..48dfe24 100644
--- a/testing/buildbot/test_suite_exceptions.pyl
+++ b/testing/buildbot/test_suite_exceptions.pyl
@@ -3129,18 +3129,12 @@
   'site_per_process_webkit_layout_tests': {
     'remove_from': [
       # chromium.linux
+      # TODO(dpranke): Should we be running this step on Linux Tests (dbg)(1)?
+      'Linux Tests (dbg)(1)',
       'Linux Tests (dbg)(1)(32)',
       # chromium.sandbox
       'Linux Tests SANDBOX',
     ],
-    'modifications': {
-      # chromium.linux
-      'Linux Tests (dbg)(1)': {
-        'args': [
-          '--debug',
-        ],
-      },
-    },
   },
   'sizes': {
     'remove_from': [
@@ -3775,6 +3769,7 @@
       'Chromium Mac 10.11',
       'Out of Process Profiling Mac',
       # chromium.linux
+      'Linux Tests (dbg)(1)',
       'Linux Tests (dbg)(1)(32)',
       # chromium.mac
       'Mac10.9 Tests',
@@ -3829,11 +3824,6 @@
           'shards': 6,
         },
       },
-      'Linux Tests (dbg)(1)': {
-        'args': [
-          '--debug',
-        ],
-      },
       # chromium.sandbox
       'Linux Tests SANDBOX': {
         'swarming': {