Chrome Cleaner: collect srt field trial group name

Bug: 
Change-Id: Ib77d051ef0813cd63eafd92b578919f46982d26b
Reviewed-on: https://chromium-review.googlesource.com/700992Reviewed-by: Chris Sharp <csharp@chromium.org>
Commit-Queue: Fabio Tirelo <ftirelo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#506527}

chrome/browser/safe_browsing/chrome_cleaner/chrome_cleaner_runner_win.cc

@@ -131,6 +131,12 @@ ChromeCleanerRunner::ChromeCleanerRunner(
     cleaner_command_line_.AppendSwitch(
         chrome_cleaner::kEnableCrashReportingSwitch);
   }
+
+  const std::string group_name = GetSRTFieldTrialGroupName();
+  if (!group_name.empty()) {
+    cleaner_command_line_.AppendSwitchASCII(
+        chrome_cleaner::kSRTPromptFieldTrialGroupNameSwitch, group_name);
+  }
 }
 
 ChromeCleanerRunner::ProcessStatus

chrome/browser/safe_browsing/chrome_cleaner/reporter_runner_win.cc

@@ -955,9 +955,16 @@ class ReporterRunner : public chrome::BrowserListObserver {
                             Now().ToInternalValue());
     }
 
-    if (ChromeMetricsServiceAccessor::IsMetricsAndCrashReportingEnabled())
+    if (ChromeMetricsServiceAccessor::IsMetricsAndCrashReportingEnabled()) {
       next_invocation->command_line.AppendSwitch(
           chrome_cleaner::kEnableCrashReportingSwitch);
+    }
+
+    const std::string group_name = GetSRTFieldTrialGroupName();
+    if (!group_name.empty()) {
+      next_invocation->command_line.AppendSwitchASCII(
+          chrome_cleaner::kSRTPromptFieldTrialGroupNameSwitch, group_name);
+    }
   }
 
   // Adds switches to be sent to the Software Reporter when the user opted into

chrome/browser/safe_browsing/chrome_cleaner/srt_field_trial_win.cc

@@ -107,6 +107,10 @@ std::string GetIncomingSRTSeed() {
                                             kSRTPromptSeedParam);
 }
 
+std::string GetSRTFieldTrialGroupName() {
+  return base::FieldTrialList::FindFullName(kSRTPromptTrial);
+}
+
 void RecordSRTPromptHistogram(SRTPromptHistogramValue value) {
   UMA_HISTOGRAM_ENUMERATION("SoftwareReporter.PromptUsage", value,
                             SRT_PROMPT_MAX);

chrome/browser/safe_browsing/chrome_cleaner/srt_field_trial_win.h

@@ -76,6 +76,9 @@ GURL GetSRTDownloadURL();
 // Returns the value of the incoming SRT seed.
 std::string GetIncomingSRTSeed();
 
+// Returns the group name in the SRTPrompt field trial.
+std::string GetSRTFieldTrialGroupName();
+
 // Records a value for the SRT Prompt Histogram.
 void RecordSRTPromptHistogram(SRTPromptHistogramValue value);
 

components/chrome_cleaner/public/constants/constants.cc

@@ -21,6 +21,7 @@ const char kExtendedSafeBrowsingEnabledSwitch[] =
     "extended-safebrowsing-enabled";
 const char kRegistrySuffixSwitch[] = "registry-suffix";
 const char kSessionIdSwitch[] = "session-id";
+const char kSRTPromptFieldTrialGroupNameSwitch[] = "srt-field-trial-group-name";
 const char kUmaUserSwitch[] = "uma-user";
 
 // Registry paths and subkeys.

components/chrome_cleaner/public/constants/constants.h

@@ -59,6 +59,9 @@ extern const char kRegistrySuffixSwitch[];
 /// binary, each generating a report). An ASCII, base-64 encoded random string.
 extern const char kSessionIdSwitch[];
 
+// Indicates the group name for the SRTPrompt field trial.
+extern const char kSRTPromptFieldTrialGroupNameSwitch[];
+
 // Indicates that metrics reporting is enabled for the current user.
 extern const char kUmaUserSwitch[];