Quota: Update field trial config to match Finch

The Finch configs for the Quota Expansion experiment were updated to
use groups that better suited our experiment.  This change rectifies the
disconnect between the field trial testing config which is a prequisite
to moving an experiment into the beta channel.

Change-Id: I469ff653bac1a6634c762a7c49ac6e75bb7ce7ea
Reviewed-on: https://chromium-review.googlesource.com/c/1492672
Commit-Queue: Jarryd Goodman <jarrydg@chromium.org>
Reviewed-by: Victor Costan <pwnall@chromium.org>
Reviewed-by: Steven Holte <holte@chromium.org>
Cr-Commit-Position: refs/heads/master@{#636657}

testing/variations/fieldtrial_testing_config.json

@@ -3898,97 +3898,17 @@
         {
             "platforms": [
                 "android",
-                "ios",
+                "chromeos",
                 "linux",
                 "mac",
                 "windows"
             ],
             "experiments": [
                 {
-                    "name": "Enabled_Pool_TwoThirds_Origin_OneFifth",
-                    "params": {
-                        "PerHostPortion": "0.2",
-                        "PoolSizeRatio": "0.6666666666666666"
-                    },
-                    "enable_features": [
-                        "QuotaExpandPoolSize"
-                    ]
-                },
-                {
-                    "name": "Enabled_Pool_ThreeQuarters_Origin_OneFifth",
-                    "params": {
-                        "PerHostPortion": "0.2",
-                        "PoolSizeRatio": "0.75"
-                    },
-                    "enable_features": [
-                        "QuotaExpandPoolSize"
-                    ]
-                },
-                {
-                    "name": "Enabled_Pool_Full_Origin_OneFifth",
-                    "params": {
-                        "PerHostPortion": "0.2",
-                        "PoolSizeRatio": "1.0"
-                    },
-                    "enable_features": [
-                        "QuotaExpandPoolSize"
-                    ]
-                },
-                {
-                    "name": "Enabled_Pool_TwoThirds_Origin_OneHalf",
-                    "params": {
-                        "PerHostPortion": "0.5",
-                        "PoolSizeRatio": "0.6666666666666666"
-                    },
-                    "enable_features": [
-                        "QuotaExpandPoolSize"
-                    ]
-                },
-                {
-                    "name": "Enabled_Pool_ThreeQuarters_Origin_OneHalf",
-                    "params": {
-                        "PerHostPortion": "0.5",
-                        "PoolSizeRatio": "0.75"
-                    },
-                    "enable_features": [
-                        "QuotaExpandPoolSize"
-                    ]
-                },
-                {
-                    "name": "Enabled_Pool_Full_Origin_OneHalf",
-                    "params": {
-                        "PerHostPortion": "0.5",
-                        "PoolSizeRatio": "1.0"
-                    },
-                    "enable_features": [
-                        "QuotaExpandPoolSize"
-                    ]
-                },
-                {
-                    "name": "Enabled_Pool_TwoThirds_Origin_TwoThirds",
-                    "params": {
-                        "PerHostPortion": "0.6666666666666666",
-                        "PoolSizeRatio": "0.6666666666666666"
-                    },
-                    "enable_features": [
-                        "QuotaExpandPoolSize"
-                    ]
-                },
-                {
-                    "name": "Enabled_Pool_ThreeQuarters_Origin_TwoThirds",
-                    "params": {
-                        "PerHostPortion": "0.6666666666666666",
-                        "PoolSizeRatio": "0.75"
-                    },
-                    "enable_features": [
-                        "QuotaExpandPoolSize"
-                    ]
-                },
-                {
-                    "name": "Enabled_Pool_Full_Origin_TwoThirds",
+                    "name": "Enabled_Pool_Four_Fifths_Origin_ThreeQuarters",
                     "params": {
-                        "PerHostPortion": "0.6666666666666666",
-                        "PoolSizeRatio": "1.0"
+                        "PerHostRatio": "0.75",
+                        "PoolSizeRatio": "0.8"
                     },
                     "enable_features": [
                         "QuotaExpandPoolSize"