[Extensions] Adjust field trial for reporting abuse on uninstall

Experiments should be set up/defined on the Finch server, not in Chromium
code. Remove the definition.

BUG=441377

Review URL: https://codereview.chromium.org/1024493003

Cr-Commit-Position: refs/heads/master@{#322253}

chrome/browser/extensions/extension_uninstall_dialog.cc

@@ -129,26 +129,8 @@ std::string ExtensionUninstallDialog::GetHeadingText() {
 }
 
 bool ExtensionUninstallDialog::ShouldShowReportAbuseCheckbox() const {
-  static const char kExperimentName[] = "ExtensionUninstall.ReportAbuse";
-  static const char kDefaultGroupName[] = "Default";
-  static const char kShowCheckboxGroup[] = "ShowCheckbox";
-
-  // Important: Only initialize the trial once.
-  if (!base::FieldTrialList::Find(kExperimentName)) {
-    // TODO(devlin): Turn on this field trial. See crbug.com/441377.
-    scoped_refptr<base::FieldTrial> trial(
-        base::FieldTrialList::FactoryGetFieldTrial(
-            kExperimentName,
-            100,  // Total probability.
-            kDefaultGroupName,
-            2015, 7, 31,  // End date.
-            base::FieldTrial::ONE_TIME_RANDOMIZED,
-            nullptr));
-    trial->AppendGroup(kShowCheckboxGroup, 0);
-  }
-
-  return base::FieldTrialList::FindFullName(kExperimentName) ==
-      kShowCheckboxGroup;
+  return base::FieldTrialList::FindFullName("ExtensionUninstall.ReportAbuse") ==
+      "ShowCheckbox";
 }
 
 void ExtensionUninstallDialog::HandleReportAbuse() {