Upstream oodles of Chrome for Android code into Chromium.

chrome/android/java_staging/src/org/chromium/chrome/browser/tabmodel/TabModelSelectorUma.java

Index: chrome/android/java_staging/src/org/chromium/chrome/browser/tabmodel/TabModelSelectorUma.java
diff --git a/chrome/android/java_staging/src/org/chromium/chrome/browser/tabmodel/TabModelSelectorUma.java b/chrome/android/java_staging/src/org/chromium/chrome/browser/tabmodel/TabModelSelectorUma.java
new file mode 100644
index 0000000000000000000000000000000000000000..e00960acfebdacc117a6bec772418605b5372687
--- /dev/null
+++ b/chrome/android/java_staging/src/org/chromium/chrome/browser/tabmodel/TabModelSelectorUma.java
@@ -0,0 +1,116 @@
+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.chrome.browser.tabmodel;
+
+import android.app.Activity;
+import android.os.SystemClock;
+
+import org.chromium.base.ActivityState;
+import org.chromium.base.ApplicationStatus;
+import org.chromium.base.metrics.RecordHistogram;
+import org.chromium.base.metrics.RecordUserAction;
+
+/**
+ * Centralizes UMA data collection for TabModelSelector. All calls must be made from the UI thread.
+ */
+public final class TabModelSelectorUma implements ApplicationStatus.ActivityStateListener {
+    // TabRestoreUserAction defined in tools/metrics/histograms/histograms.xml.
+    private static final int USER_WAITED_FOR_RESTORE_COMPLETION = 0;
+    private static final int USER_LEFT_TAB_DURING_RESTORE = 1;
+    private static final int USER_LEFT_CHROME_DURING_RESTORE = 2;
+    private static final int USER_ACTION_DURING_RESTORE_MAX = 3;
+
+    // Id of the active tab being restored. Equals -1 when the active tab is not being restored.
+    private int mRestoredTabId = -1;
+    // Timestamp of the beginning of the most recent tab restore.
+    private long mRestoreStartedAtMsec = -1;
+
+    TabModelSelectorUma(Activity activity) {
+        ApplicationStatus.registerStateListenerForActivity(this, activity);
+    }
+
+    /**
+     * Cleans up any external dependencies of this class.
+     */
+    public void destroy() {
+        ApplicationStatus.unregisterActivityStateListener(this);
+    }
+
+    @Override
+    public void onActivityStateChange(Activity activity, int newState) {
+        if (newState != ActivityState.STOPPED) return;
+        if (mRestoredTabId != -1) {
+            recordUserActionDuringTabRestore(USER_LEFT_CHROME_DURING_RESTORE);
+            mRestoredTabId = -1;
+        }
+    }
+
+    void userSwitchedToTab() {
+        RecordUserAction.record("MobileTabSwitched");
+    }
+
+    void onShowTab(int tabId, boolean isBeingRestored) {
+        if (mRestoredTabId != -1 && tabId != mRestoredTabId) {
+            recordUserActionDuringTabRestore(USER_LEFT_TAB_DURING_RESTORE);
+            mRestoredTabId = -1;
+        }
+        if (isBeingRestored) {
+            mRestoredTabId = tabId;
+            mRestoreStartedAtMsec = nowMsec();
+        }
+    }
+
+    void onTabClosing(int tabId) {
+        if (mRestoredTabId != -1 && tabId == mRestoredTabId) {
+            recordUserActionDuringTabRestore(USER_LEFT_TAB_DURING_RESTORE);
+            mRestoredTabId = -1;
+        }
+    }
+
+    void onTabCrashed(int tabId) {
+        if (mRestoredTabId != -1 && tabId == mRestoredTabId) {
+            mRestoredTabId = -1;
+        }
+    }
+
+    void onPageLoadFinished(int tabId) {
+        if (mRestoredTabId != -1 && tabId == mRestoredTabId) {
+            recordUserActionDuringTabRestore(USER_WAITED_FOR_RESTORE_COMPLETION);
+            mRestoredTabId = -1;
+        }
+    }
+
+    void onPageLoadFailed(int tabId) {
+        if (mRestoredTabId != -1 && tabId == mRestoredTabId) {
+            assert mRestoreStartedAtMsec != -1;
+            // If the pageload fails very quickly we cannot argue that the user "waited for
+            // completion".
+            if (nowMsec() - mRestoreStartedAtMsec >= 5000) {
+                recordUserActionDuringTabRestore(USER_WAITED_FOR_RESTORE_COMPLETION);
+            }
+            mRestoredTabId = -1;
+        }
+    }
+
+    void onTabsViewShown() {
+        if (mRestoredTabId != -1) {
+            recordUserActionDuringTabRestore(USER_LEFT_TAB_DURING_RESTORE);
+            mRestoredTabId = -1;
+        }
+    }
+
+    private static long nowMsec() {
+        return SystemClock.elapsedRealtime();
+    }
+
+    /**
+     * Logs action to a UMA histogram.
+     */
+    private void recordUserActionDuringTabRestore(int action) {
+        assert action >= 0 && action < USER_ACTION_DURING_RESTORE_MAX;
+        RecordHistogram.recordEnumeratedHistogram(
+                "Tab.RestoreUserPersistence", action, USER_ACTION_DURING_RESTORE_MAX);
+    }
+}