Fix main intent background duration startup metrics.

Accidentally broken by this refactoring:
https://chromium-review.googlesource.com/582338

Added tests to ensure the metric does not regress in the future.

BUG=800625

Change-Id: Iae1e29d11f62f177cea1200fa24befa64b77f559
Reviewed-on: https://chromium-review.googlesource.com/879433
Commit-Queue: Ted Choc <tedchoc@chromium.org>
Reviewed-by: Maria Khomenko <mariakhomenko@chromium.org>
Cr-Commit-Position: refs/heads/master@{#531708}

chrome/android/java/src/org/chromium/chrome/browser/ChromeTabbedActivity.java

@@ -214,7 +214,8 @@ public class ChromeTabbedActivity
     private static final String ACTION_CLOSE_TABS =
             "com.google.android.apps.chrome.ACTION_CLOSE_TABS";
 
-    private static final String LAST_BACKGROUNDED_TIME_MS_PREF =
+    @VisibleForTesting
+    public static final String LAST_BACKGROUNDED_TIME_MS_PREF =
             "ChromeTabbedActivity.BackgroundTimeMs";
     private static final String NTP_LAUNCH_DELAY_IN_MINS_PARAM = "delay_in_mins";
 
@@ -982,8 +983,7 @@ public class ChromeTabbedActivity
 
     private void logMainIntentBehavior(Intent intent) {
         assert isMainIntentFromLauncher(intent);
-        long currentTime = System.currentTimeMillis();
-        mMainIntentMetrics.onMainIntentWithNative(currentTime - getTimeSinceLastBackgroundedMs());
+        mMainIntentMetrics.onMainIntentWithNative(getTimeSinceLastBackgroundedMs());
     }
 
     /** Access the main intent metrics for test validation. */
@@ -1110,9 +1110,13 @@ public class ChromeTabbedActivity
      * Returns the number of milliseconds since Chrome was last backgrounded.
      */
     private long getTimeSinceLastBackgroundedMs() {
-        long lastBackgroundedTimeMs =
-                ContextUtils.getAppSharedPreferences().getLong(LAST_BACKGROUNDED_TIME_MS_PREF, -1);
-        return System.currentTimeMillis() - lastBackgroundedTimeMs;
+        // TODO(tedchoc): We should cache the last visible time and reuse it to avoid different
+        //                values of this depending on when it is called after the activity was
+        //                shown.
+        long currentTime = System.currentTimeMillis();
+        long lastBackgroundedTimeMs = ContextUtils.getAppSharedPreferences().getLong(
+                LAST_BACKGROUNDED_TIME_MS_PREF, currentTime);
+        return currentTime - lastBackgroundedTimeMs;
     }
 
     @Override

chrome/android/javatests/src/org/chromium/chrome/browser/metrics/MainIntentBehaviorMetricsIntegrationTest.java

@@ -4,18 +4,25 @@
 
 package org.chromium.chrome.browser.metrics;
 
+import static org.junit.Assert.assertThat;
+
+import android.annotation.SuppressLint;
 import android.content.ComponentName;
 import android.content.Intent;
 import android.support.test.InstrumentationRegistry;
 import android.support.test.filters.MediumTest;
 
+import org.hamcrest.Matchers;
+import org.junit.After;
 import org.junit.Assert;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 
+import org.chromium.base.ContextUtils;
 import org.chromium.base.ThreadUtils;
 import org.chromium.base.test.util.CommandLineFlags;
+import org.chromium.base.test.util.UserActionTester;
 import org.chromium.chrome.R;
 import org.chromium.chrome.browser.ChromeSwitches;
 import org.chromium.chrome.browser.ChromeTabbedActivity;
@@ -37,11 +44,21 @@ import java.util.concurrent.Callable;
  */
 @RunWith(ChromeJUnit4ClassRunner.class)
 @CommandLineFlags.Add({ChromeSwitches.DISABLE_FIRST_RUN_EXPERIENCE})
+@SuppressLint({"ApplySharedPref", "CommitPrefEdits"})
 public class MainIntentBehaviorMetricsIntegrationTest {
+    private static final long HOURS_IN_MS = 60 * 60 * 1000L;
+
     @Rule
     public ChromeActivityTestRule<ChromeTabbedActivity> mActivityTestRule =
             new ChromeActivityTestRule<>(ChromeTabbedActivity.class);
 
+    private UserActionTester mActionTester;
+
+    @After
+    public void tearDown() {
+        if (mActionTester != null) mActionTester.tearDown();
+    }
+
     @MediumTest
     @Test
     public void testFocusOmnibox() {
@@ -137,6 +154,66 @@ public class MainIntentBehaviorMetricsIntegrationTest {
                 .getPendingActionRecordForMainIntent());
     }
 
+    @MediumTest
+    @Test
+    public void testBackgroundDuration_24hrs() {
+        assertBackgroundDurationLogged(
+                24 * HOURS_IN_MS, "MobileStartup.MainIntentReceived.After24Hours");
+    }
+
+    @MediumTest
+    @Test
+    public void testBackgroundDuration_12hrs() {
+        assertBackgroundDurationLogged(
+                12 * HOURS_IN_MS, "MobileStartup.MainIntentReceived.After12Hours");
+    }
+
+    @MediumTest
+    @Test
+    public void testBackgroundDuration_6hrs() {
+        assertBackgroundDurationLogged(
+                6 * HOURS_IN_MS, "MobileStartup.MainIntentReceived.After6Hours");
+    }
+
+    @MediumTest
+    @Test
+    public void testBackgroundDuration_1hr() {
+        assertBackgroundDurationLogged(HOURS_IN_MS, "MobileStartup.MainIntentReceived.After1Hour");
+    }
+
+    @MediumTest
+    @Test
+    public void testBackgroundDuration_0hr() {
+        assertBackgroundDurationLogged(0, null);
+        for (String action : mActionTester.getActions()) {
+            if (action.startsWith("MobileStartup.MainIntentReceived.After")) {
+                Assert.fail("Unexpected background duration logged: " + action);
+            }
+        }
+    }
+
+    private void assertBackgroundDurationLogged(long duration, String expectedMetric) {
+        startActivity(false);
+        mActionTester = new UserActionTester();
+        ContextUtils.getAppSharedPreferences()
+                .edit()
+                .putLong(ChromeTabbedActivity.LAST_BACKGROUNDED_TIME_MS_PREF,
+                        System.currentTimeMillis() - duration)
+                .commit();
+
+        Intent intent = new Intent(Intent.ACTION_MAIN);
+        intent.addCategory(Intent.CATEGORY_LAUNCHER);
+        ThreadUtils.runOnUiThreadBlocking(
+                () -> { mActivityTestRule.getActivity().onNewIntent(intent); });
+
+        assertThat(mActionTester.toString(), mActionTester.getActions(),
+                Matchers.hasItem("MobileStartup.MainIntentReceived"));
+        if (expectedMetric != null) {
+            assertThat(mActionTester.toString(), mActionTester.getActions(),
+                    Matchers.hasItem(expectedMetric));
+        }
+    }
+
     private void startActivity(boolean addLauncherCategory) {
         Intent intent = new Intent(Intent.ACTION_MAIN);
         intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);