Update WebAPK if homescreen icon changed.

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

Index: chrome/android/java/src/org/chromium/chrome/browser/ShortcutHelper.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/ShortcutHelper.java b/chrome/android/java/src/org/chromium/chrome/browser/ShortcutHelper.java
index 6aef70fc5d81046a2cc4ac6be6692d7b533fac2e..2d2cf272a4e795e8c881ff9483afc23ff06284ea 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/ShortcutHelper.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/ShortcutHelper.java
@@ -39,6 +39,7 @@ import org.chromium.chrome.browser.webapps.WebappDataStorage;
 import org.chromium.chrome.browser.webapps.WebappLauncherActivity;
 import org.chromium.chrome.browser.webapps.WebappRegistry;
 import org.chromium.chrome.browser.widget.RoundedIconGenerator;
+import org.chromium.content_public.browser.WebContents;
 import org.chromium.content_public.common.ScreenOrientationConstants;
 import org.chromium.net.GURLUtils;
 import org.chromium.ui.widget.Toast;
@@ -101,6 +102,14 @@ public class ShortcutHelper {
     private static final float GENERATED_ICON_PADDING_RATIO = 1.0f / 12.0f;
     private static final float GENERATED_ICON_FONT_SIZE_RATIO = 1.0f / 3.0f;
 
+    /**
+     * Callback to {@link fetchHomescreenImage()}. Called once the homescreen image has been
+     * fetched.
+     */
+    public interface FetchHomescreenImageCallback {
+        public void onFetchedHomescreenImage(Bitmap bitmap, long murmur2Hash);
+    }
+
     /** Broadcasts Intents out Android for adding the shortcut. */
     public static class Delegate {
         /**
@@ -446,6 +455,24 @@ public class ShortcutHelper {
     }
 
     /**
+     * Fetches the image at {@link iconUrl} and scales it so that it can be used on the homescreen.
+     */
+    public static void fetchHomescreenImage(
+            WebContents webContents, String imageUrl, FetchHomescreenImageCallback callback) {
+        nativeFetchHomescreenImage(webContents, imageUrl, callback);
+    }
+
+    /**
+     * Called once the image requested by {@link #fetchHomescreenImage()} is fetched in order to run
+     * the Java callback.
+     */
+    @CalledByNative
+    public static void onFetchedHomescreenImage(
+            Bitmap bitmap, long murmur2Hash, FetchHomescreenImageCallback callback) {
+        callback.onFetchedHomescreenImage(bitmap, murmur2Hash);
+    }
+
+    /**
      * Returns true if WebAPKs are enabled and there is a WebAPK installed which can handle
      * {@link url}.
      */
@@ -602,5 +629,7 @@ public class ShortcutHelper {
         return null;
     }
 
+    private static native void nativeFetchHomescreenImage(
+            WebContents webContents, String imageUrl, FetchHomescreenImageCallback callback);
     private static native void nativeOnWebappDataStored(long callbackPointer);
 }