SimpleCache: Add fieldtrial testing information.

This came up as a warning for a new finch trial advancing these to
beta.

R=asvitkine
BUG=490029

Review URL: https://codereview.chromium.org/1790483003

Cr-Commit-Position: refs/heads/master@{#381718}

testing/variations/fieldtrial_testing_config_chromeos.json

@@ -140,6 +140,11 @@
             "group_name": "Enabled"
         }
     ],
+    "SimpleCacheTrial": [
+        {
+            "group_name": "ExperimentYes"
+        }
+    ],
     "SpdyEnableDependencies": [
         {
             "group_name": "Enable"

testing/variations/fieldtrial_testing_config_linux.json

@@ -187,6 +187,11 @@
             "group_name": "Enabled"
         }
     ],
+    "SimpleCacheTrial": [
+        {
+            "group_name": "ExperimentYes"
+        }
+    ],
     "SpdyEnableDependencies": [
         {
             "group_name": "Enable"

testing/variations/fieldtrial_testing_config_mac.json

@@ -203,6 +203,11 @@
             "group_name": "Enabled"
         }
     ],
+    "SimpleCacheTrial": [
+        {
+            "group_name": "ExperimentYes"
+        }
+    ],
     "SpdyEnableDependencies": [
         {
             "group_name": "Enable"

testing/variations/fieldtrial_testing_config_win.json

@@ -280,6 +280,11 @@
             "group_name": "enforce_always_with_extensions_and_dse"
         }
     ],
+    "SimpleCacheTrial": [
+        {
+            "group_name": "ExperimentYes"
+        }
+    ],
     "SpdyEnableDependencies": [
         {
             "group_name": "Enable"