Hook up Reader Mode InfoBar

chrome/android/java/src/org/chromium/chrome/browser/dom_distiller/ReaderModeTabInfo.java

Index: chrome/android/java/src/org/chromium/chrome/browser/dom_distiller/ReaderModeTabInfo.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/dom_distiller/ReaderModeTabInfo.java b/chrome/android/java/src/org/chromium/chrome/browser/dom_distiller/ReaderModeTabInfo.java
index ef50dc74f30180ea38d63a543bcd73d3e6f7ab6d..9f9a2c2b7e6350129769e7f1cfdb038b7c5621ae 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/dom_distiller/ReaderModeTabInfo.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/dom_distiller/ReaderModeTabInfo.java
@@ -4,6 +4,8 @@
 
 package org.chromium.chrome.browser.dom_distiller;
 
+import android.os.SystemClock;
+
 import org.chromium.content_public.browser.WebContentsObserver;
 
 /**
@@ -30,6 +32,12 @@ public class ReaderModeTabInfo {
     // Used to flag the the panel was shown and recorded by UMA.
     private boolean mShowPanelRecorded;
 
+    // The time that the user started viewing Reader Mode content.
+    private long mViewStartTimeMs;
+
+    // Whether or not the current tab is a Reader Mode page.
+    private boolean mIsViewingReaderModePage;
+
     /**
      * @param observer The WebContentsObserver for the tab this object represents.
      */
@@ -45,6 +53,31 @@ public class ReaderModeTabInfo {
     }
 
     /**
+     * A notification that the user started viewing Reader Mode.
+     */
+    public void onStartedReaderMode() {
+        mIsViewingReaderModePage = true;
+        mViewStartTimeMs = SystemClock.elapsedRealtime();
+    }
+
+    /**
+     * A notification that the user is no longer viewing Reader Mode. This could be because of a
+     * navigation away from the page, switching tabs, or closing the browser.
+     * @return The amount of time in ms that the user spent viewing Reader Mode.
+     */
+    public long onExitReaderMode() {
+        mIsViewingReaderModePage = false;
+        return SystemClock.elapsedRealtime() - mViewStartTimeMs;
+    }
+
+    /**
+     * @return Whether or not the user is on a Reader Mode page.
+     */
+    public boolean isViewingReaderModePage() {
+        return mIsViewingReaderModePage;
+    }
+
+    /**
      * @param status The status of reader mode for this object's tab.
      */
     public void setStatus(int status) {