Add permission prompt UI experiments to variations testing.

testing/variations/fieldtrial_testing_config.json

 {
     "AndroidSessionNotifications": [
         {
             "platforms": [
                 "android"
             ],
             "experiments": [
                 {
                     "name": "Disabled"
                 }
@@ skipping 1372 matching lines @@
             "experiments": [
                 {
                     "name": "3-Times",
                     "params": {
                         "dismissal_count": "3"
                     }
                 }
             ]
         }
     ],
+    "PermissionPromptUIAndroid": [
+        {
+            "platforms": [
+                "android"
+            ],
+            "experiments": [
+                {
+                    "name": "ModalGestureEnabled",
+                    "params": {
+                        "require_gesture": "true"
+                    },
+                    "enable_features": [
+                        "ModalPermissionPrompts"
+                    ],
+                    "disable_features": [
+                        "DisplayPersistenceToggleInPermissionPrompts"
+                    ]
+                },
+                {
+                    "name": "ModalNoGestureEnabled",
+                    "params": {
+                        "require_gesture": "false"
+                    },
+                    "enable_features": [
+                        "ModalPermissionPrompts"
+                    ],
+                    "disable_features": [
+                        "DisplayPersistenceToggleInPermissionPrompts"
+                    ]
+                },
+                {
+                    "name": "ModalAndToggleEnabled",
+                    "params": {
+                        "require_gesture": "false"
+                    },
+                    "enable_features": [
+                        "DisplayPersistenceToggleInPermissionPrompts",
+                        "ModalPermissionPrompts"
+                    ]
+                },
+                {
+                    "name": "ToggleEnabled",
+                    "enable_features": [
+                        "DisplayPersistenceToggleInPermissionPrompts"
+                    ],
+                    "disable_features": [
+                        "ModalPermissionPrompts"
+                    ]
+                }

[Ilya Sherman, 2016/12/20 01:19:54]

Note that only the first of the listed experiments will be tested, and should
therefore be the experiment that you expect to launch.  Listing the other
experiments is optional.

[dominickn, 2016/12/20 06:54:20]

Thanks. The first experiment is most likely to launch, but we will see what the
1% experiment on stable tells us before proceeding.

+            ]
+        }
+    ],
+    "PermissionPromptUIViews": [
+        {
+            "platforms": [
+                "chromeos",
+                "linux",
+                "win"
+            ],
+            "experiments": [
+                {
+                    "name": "ToggleEnabled",
+                    "enable_features": [
+                        "DisplayPersistenceToggleInPermissionPrompts"
+                    ]
+                }
+            ]
+        }
+    ],
     "PersistentHistograms": [
         {
             "platforms": [
                 "android",
                 "chromeos",
                 "ios",
                 "linux",
                 "mac",
                 "win"
             ],
@@ skipping 1057 matching lines @@
                 {
                     "name": "Enabled",
                     "enable_features": [
                         "use-new-media-cache"
                     ]
                 }
             ]
         }
     ]
 }