webapps: initial addition of splash screen icon downloading

chrome/android/java/src/org/chromium/chrome/browser/webapps/WebappDataStorage.java

Index: chrome/android/java/src/org/chromium/chrome/browser/webapps/WebappDataStorage.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/webapps/WebappDataStorage.java b/chrome/android/java/src/org/chromium/chrome/browser/webapps/WebappDataStorage.java
index 2540b8d95acab7e81d64cbd9ee4219b2384f8ea2..cec10d4086f970465b7aab6023134ce576d1acfd 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/webapps/WebappDataStorage.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/webapps/WebappDataStorage.java
@@ -10,6 +10,7 @@ import android.graphics.Bitmap;
 import android.os.AsyncTask;
 
 import org.chromium.base.ThreadUtils;
+import org.chromium.base.VisibleForTesting;
 import org.chromium.chrome.browser.ShortcutHelper;
 
 /**
@@ -38,6 +39,8 @@ public class WebappDataStorage {
     static final String KEY_SPLASH_ICON = "splash_icon";
     static final String KEY_LAST_USED = "last_used";
 
+    private static Observer sObserver = null;
+
     private final SharedPreferences mPreferences;
 
     /**
@@ -84,6 +87,14 @@ public class WebappDataStorage {
         }.execute();
     }
 
+    /**
+     * Sets the observer to use.
+     */
+    @VisibleForTesting
+    public static void setObserverForTests(Observer observer) {
+        sObserver = observer;
+    }
+
     /* Package private for use by WebappRegistry */
     WebappDataStorage(Context context, String webappId) {
         mPreferences = context.getSharedPreferences(
@@ -105,6 +116,7 @@ public class WebappDataStorage {
      * @param splashScreenImage The image which should be shown on the splash screen of the webapp.
      */
     public void updateSplashScreenImage(Bitmap splashScreenImage) {
+        if (sObserver != null) sObserver.onUpdateSplashScreenImage(splashScreenImage);
         new UpdateTask(splashScreenImage).execute();
     }
 
@@ -126,6 +138,17 @@ public class WebappDataStorage {
         public void onDataRetrieved(T readObject);
     }
 
+    /**
+     * Observer used to monitor splash screen downloads.
+     */
+    public static interface Observer {

[mlamouri (slow - plz ping), 2015/09/02 16:56:57]

You are adding this observer interface just for tests? That doesn't sound like a
good idea. Could you think of another way to run the test without the observer?

[Lalit Maganti, 2015/09/02 17:15:42]

It was on Dan's suggestion. The other way I can think of is to simply run the
tests and observe the changes in the SharedPreferences but since there are
instrumentation tests that would be quite brittle.

I think this is quite common as it is done in AppDetailsDelegate.Observer for
example. I'll add a VisibleForTesting annotation like is done there though.

+
+        /**
+         * Called when a splash screen update is queued.
+         */
+        public void onUpdateSplashScreenImage(Bitmap image);
+    }
+
     private final class BitmapFetchTask extends AsyncTask<Void, Void, Bitmap> {
 
         private final String mKey;