Android FRE: Use CachedMetrics API for histograms.

chrome/android/java/src/org/chromium/chrome/browser/firstrun/FirstRunActivity.java

Index: chrome/android/java/src/org/chromium/chrome/browser/firstrun/FirstRunActivity.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/firstrun/FirstRunActivity.java b/chrome/android/java/src/org/chromium/chrome/browser/firstrun/FirstRunActivity.java
index d1e80333476fc87ed23956cb34b76b0a7778b856..dc6ba8970f9f2e1a0b7170e28f05dff41c0599a9 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/firstrun/FirstRunActivity.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/firstrun/FirstRunActivity.java
@@ -17,7 +17,7 @@ import org.chromium.base.ApplicationStatus;
 import org.chromium.base.Log;
 import org.chromium.base.VisibleForTesting;
 import org.chromium.base.library_loader.ProcessInitException;
-import org.chromium.base.metrics.RecordHistogram;
+import org.chromium.base.metrics.CachedMetrics.EnumeratedHistogramSample;
 import org.chromium.chrome.R;
 import org.chromium.chrome.browser.ChromeApplication;
 import org.chromium.chrome.browser.EmbedContentViewActivity;
@@ -69,25 +69,26 @@ public class FirstRunActivity extends AppCompatActivity implements FirstRunPageD
     public static final boolean DEFAULT_METRICS_AND_CRASH_REPORTING = true;
 
     // UMA constants.
-    private static final String UMA_SIGNIN_CHOICE = "MobileFre.SignInChoice";
     private static final int SIGNIN_SETTINGS_DEFAULT_ACCOUNT = 0;
     private static final int SIGNIN_SETTINGS_ANOTHER_ACCOUNT = 1;
     private static final int SIGNIN_ACCEPT_DEFAULT_ACCOUNT = 2;
     private static final int SIGNIN_ACCEPT_ANOTHER_ACCOUNT = 3;
     private static final int SIGNIN_NO_THANKS = 4;
-    private static final int SIGNIN_OPTION_COUNT = 5;
+    private static final int SIGNIN_MAX = 5;
+    private static final EnumeratedHistogramSample sSigninChoiceHistogram =
+            new EnumeratedHistogramSample("MobileFre.SignInChoice", SIGNIN_MAX);
 
-    private static final String FRE_ENTRY_MAIN_INTENT = ".MainIntent";
-    private static final String FRE_ENTRY_VIEW_INTENT = ".ViewIntent";
-
-    private static final String UMA_FRE_PROGRESS = "MobileFre.Progress";
     private static final int FRE_PROGRESS_STARTED = 0;
     private static final int FRE_PROGRESS_WELCOME_SHOWN = 1;
     private static final int FRE_PROGRESS_DATA_SAVER_SHOWN = 2;
     private static final int FRE_PROGRESS_SIGNIN_SHOWN = 3;
     private static final int FRE_PROGRESS_COMPLETED_SIGNED_IN = 4;
     private static final int FRE_PROGRESS_COMPLETED_NOT_SIGNED_IN = 5;
-    private static final int FRE_PROGRESS_TERMINATOR = 6;
+    private static final int FRE_PROGRESS_MAX = 6;
+    private static final EnumeratedHistogramSample sMobileFreProgressMainIntentHistogram =
+            new EnumeratedHistogramSample("MobileFre.SignInChoice.MainIntent", FRE_PROGRESS_MAX);
+    private static final EnumeratedHistogramSample sMobileFreProgressViewIntentHistogram =
+            new EnumeratedHistogramSample("MobileFre.SignInChoice.ViewIntent", FRE_PROGRESS_MAX);
 
     @VisibleForTesting
     static FirstRunGlue sGlue = new FirstRunGlueImpl();
@@ -304,9 +305,7 @@ public class FirstRunActivity extends AppCompatActivity implements FirstRunPageD
                     choice = SIGNIN_ACCEPT_ANOTHER_ACCOUNT;
                 }
             }
-            RecordHistogram.recordEnumeratedHistogram(
-                    UMA_SIGNIN_CHOICE, choice, SIGNIN_OPTION_COUNT);
-
+            sSigninChoiceHistogram.record(choice);
             recordFreProgressHistogram(FRE_PROGRESS_COMPLETED_SIGNED_IN);
         } else {
             recordFreProgressHistogram(FRE_PROGRESS_COMPLETED_NOT_SIGNED_IN);
@@ -337,8 +336,7 @@ public class FirstRunActivity extends AppCompatActivity implements FirstRunPageD
 
     @Override
     public void refuseSignIn() {
-        RecordHistogram.recordEnumeratedHistogram(
-                UMA_SIGNIN_CHOICE, SIGNIN_NO_THANKS, SIGNIN_OPTION_COUNT);
+        sSigninChoiceHistogram.record(SIGNIN_NO_THANKS);
         mResultSignInAccountName = null;
         mResultShowSignInSettings = false;
     }
@@ -483,11 +481,11 @@ public class FirstRunActivity extends AppCompatActivity implements FirstRunPageD
     }
 
     private void recordFreProgressHistogram(int state) {
-        String entryType = mFreProperties.getBoolean(FirstRunActivity.EXTRA_COMING_FROM_CHROME_ICON)
-                ? FRE_ENTRY_MAIN_INTENT
-                : FRE_ENTRY_VIEW_INTENT;
-        RecordHistogram.recordEnumeratedHistogram(
-                UMA_FRE_PROGRESS + entryType, state, FRE_PROGRESS_TERMINATOR);
+        if (mFreProperties.getBoolean(FirstRunActivity.EXTRA_COMING_FROM_CHROME_ICON)) {
+            sMobileFreProgressMainIntentHistogram.record(state);
+        } else {
+            sMobileFreProgressViewIntentHistogram.record(state);
+        }
     }
 
     /**