Trigger the Snippets Scheduler when Resuming Activities

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

Index: chrome/android/java/src/org/chromium/chrome/browser/ChromeTabbedActivity.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/ChromeTabbedActivity.java b/chrome/android/java/src/org/chromium/chrome/browser/ChromeTabbedActivity.java
index 4701a6b175ccf433e3dcb8a43514f6115a880012..de049177a631684af32ac4a7820d7c3c1a9727d1 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/ChromeTabbedActivity.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/ChromeTabbedActivity.java
@@ -80,6 +80,8 @@ import org.chromium.chrome.browser.metrics.UmaUtils;
 import org.chromium.chrome.browser.multiwindow.MultiWindowUtils;
 import org.chromium.chrome.browser.ntp.NativePageAssassin;
 import org.chromium.chrome.browser.ntp.NewTabPageUma;
+import org.chromium.chrome.browser.ntp.snippets.SnippetsBridge;
+import org.chromium.chrome.browser.ntp.snippets.SnippetsConfig;
 import org.chromium.chrome.browser.omaha.OmahaClient;
 import org.chromium.chrome.browser.omnibox.AutocompleteController;
 import org.chromium.chrome.browser.partnercustomizations.HomepageManager;
@@ -229,6 +231,8 @@ public class ChromeTabbedActivity extends ChromeActivity implements OverviewMode
 
     private VrShellDelegate mVrShellDelegate;
 
+    private ApplicationStatus.ActivityStateListener mSnippetsSchedulerListener;
+
     private class TabbedAssistStatusHandler extends AssistStatusHandler {
         public TabbedAssistStatusHandler(Activity activity) {
             super(activity);
@@ -404,6 +408,14 @@ public class ChromeTabbedActivity extends ChromeActivity implements OverviewMode
             mLocaleManager = LocaleManager.getInstance();
             mLocaleManager.showSearchEnginePromoIfNeeded(this);
 
+            if (SnippetsConfig.isEnabled()) {
+                // The SnippetsBridge propagates the state changes so the scheduler can post
+                // deferred tasks to refresh outdated snippets.
+                mSnippetsSchedulerListener = SnippetsBridge.makeActivityStateListener();
+                ApplicationStatus.registerStateListenerForActivity(
+                        mSnippetsSchedulerListener, this);
+            }
+
             super.finishNativeInitialization();
         } finally {
             TraceEvent.end("ChromeTabbedActivity.finishNativeInitialization");
@@ -430,6 +442,11 @@ public class ChromeTabbedActivity extends ChromeActivity implements OverviewMode
 
         mLocaleManager.setSnackbarManager(getSnackbarManager());
         mLocaleManager.startObservingPhoneChanges();
+
+        // Without any interaction, this start was cold and the listener will ignore it.

[Michael van Ouwerkerk, 2017/01/04 14:32:17]

Without user interaction, it is the start of the activity. Not guaranteed to be
cold, as the native library might have been loaded already for a service or
another activity.

[fhorschig, 2017/01/04 15:04:44]

Good lead, added a check and a warm alternative call for this case.

+        if (SnippetsConfig.isEnabled() && getLastUserInteractionTime() == 0) {
+            SnippetsBridge.notifySchedulerAboutColdStart();
+        }
     }
 
     @Override
@@ -1444,6 +1461,11 @@ public class ChromeTabbedActivity extends ChromeActivity implements OverviewMode
             mVrShellDelegate.destroyVrShell();
         }
 
+        if (mSnippetsSchedulerListener != null) {
+            ApplicationStatus.unregisterActivityStateListener(mSnippetsSchedulerListener);
+            mSnippetsSchedulerListener = null;
+        }
+
         super.onDestroyInternal();
     }