Revert "Add PermissionChip feature to fieldtrial_testing_config.json."

This reverts commit 39053ccc.

Reason for revert: 

`PermissionBubbleBrowserTest.HasLocationBarByDefault` started failing in https://ci.chromium.org/p/chromium/builders/ci/Mac10.11%20Tests/57303 (and other Mac bots at the same time). Failures look like https://logs.chromium.org/logs/chromium/buildbucket/cr-buildbucket.appspot.com/8863201444294046496/+/steps/browser_tests_on__none__GPU_on_Mac_on_Mac-10.11/0/logs/Deterministic_failure:_PermissionBubbleBrowserTest.HasLocationBarByDefault__status_CRASH_/0.


Original change's description:
> Add PermissionChip feature to fieldtrial_testing_config.json.
>
> As a prerequisite to landing cr/339683181.
>
> Bug: 1134294
> Change-Id: I95a0774957c5ba1cae28faad5916865f50e5a8d7
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2510054
> Commit-Queue: Bret Sepulveda <bsep@chromium.org>
> Reviewed-by: Brian White <bcwhite@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#829185}

TBR=bcwhite@chromium.org,bsep@chromium.org,olesiamarukhno@google.com

Change-Id: I6e8f9f26c972e5681e69a909653d2d88a6184a40
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 1134294
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2550184Reviewed-by: Mike West <mkwst@chromium.org>
Commit-Queue: Mike West <mkwst@chromium.org>
Cr-Commit-Position: refs/heads/master@{#829229}

testing/variations/fieldtrial_testing_config.json

@@ -5350,24 +5350,6 @@
             ]
         }
     ],
-    "PermissionChip": [
-        {
-            "platforms": [
-                "chromeos",
-                "linux",
-                "mac",
-                "windows"
-            ],
-            "experiments": [
-                {
-                    "name": "Enabled",
-                    "enable_features": [
-                        "PermissionChip"
-                    ]
-                }
-            ]
-        }
-    ],
     "PermissionPromptUICocoa": [
         {
             "platforms": [