Plumb Notification action icons through to the UI layer.

chrome/android/java/src/org/chromium/chrome/browser/notifications/NotificationBuilderBase.java

Index: chrome/android/java/src/org/chromium/chrome/browser/notifications/NotificationBuilderBase.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/notifications/NotificationBuilderBase.java b/chrome/android/java/src/org/chromium/chrome/browser/notifications/NotificationBuilderBase.java
index 08ef5fb47bd1fc05f5ea60dc671ced168090cdcb..13c01bbbbffdbf6bb60d0968f04c24fa756062d7 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/notifications/NotificationBuilderBase.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/notifications/NotificationBuilderBase.java
@@ -4,10 +4,12 @@
 
 package org.chromium.chrome.browser.notifications;
 
+import android.annotation.TargetApi;
 import android.app.Notification;
 import android.app.PendingIntent;
 import android.graphics.Bitmap;
-import android.support.v4.app.NotificationCompat.Action;
+import android.graphics.drawable.Icon;
+import android.os.Build;
 
 import org.chromium.base.VisibleForTesting;
 
@@ -21,6 +23,25 @@
  * Abstract base class for building a notification. Stores all given arguments for later use.
  */
 public abstract class NotificationBuilderBase {
+    protected static class Action {
+        public int iconId;
+        public Bitmap iconBitmap;
+        public CharSequence title;
+        public PendingIntent intent;
+
+        Action(int iconId, CharSequence title, PendingIntent intent) {
+            this.iconId = iconId;
+            this.title = title;
+            this.intent = intent;
+        }
+
+        Action(Bitmap iconBitmap, CharSequence title, PendingIntent intent) {
+            this.iconBitmap = iconBitmap;
+            this.title = title;
+            this.intent = intent;
+        }
+    }
+
     /**
      * Maximum length of CharSequence inputs to prevent excessive memory consumption. At current
      * screen sizes we display about 500 characters at most, so this is a pretty generous limit, and
@@ -33,7 +54,7 @@
      * The maximum number of action buttons. One is for the settings button, and two more slots are
      * for developer provided buttons.
      */
-    private static final int MAX_ACTION_BUTTONS = 3;
+    private static final int MAX_ACTION_BUTTONS = 2;

[Peter Beverloo, 2016/02/10 12:29:37]

This is because addSettingsAction() will be called after author-defined action
buttons, right?

Please update the comment (which is now out of date), and consider renaming it
to MAX_AUTHOR_PROVIDED_ACTION_BUTTONS or similar.

[Michael van Ouwerkerk, 2016/02/10 17:18:12]

Done. This slipped when I moved the settings button to its own member and out of
the list.

 
     protected CharSequence mTitle;
     protected CharSequence mBody;
@@ -134,6 +155,20 @@ public NotificationBuilderBase addAction(
     }
 
     /**
+     * Adds an action to the notification. Actions are typically displayed as a button adjacent to
+     * the notification content.
+     */
+    public NotificationBuilderBase addAction(@Nullable Bitmap iconBitmap,
+            @Nullable CharSequence title, @Nullable PendingIntent intent) {
+        if (mActions.size() == MAX_ACTION_BUTTONS) {
+            throw new IllegalStateException(
+                    "Cannot add more than " + MAX_ACTION_BUTTONS + " actions.");
+        }
+        mActions.add(new Action(iconBitmap, limitLength(title), intent));
+        return this;
+    }
+
+    /**
      * Adds an action to the notification for opening the settings screen.
      */
     public NotificationBuilderBase addSettingsAction(
@@ -183,4 +218,20 @@ private static CharSequence limitLength(@Nullable CharSequence input) {
         }
         return input;
     }
+
+    /**
+     * Adds an action to {@code builder} using a {@code Bitmap} if possible, and otherwise a
+     * resource id if it is set.
+     */
+    @SuppressWarnings("deprecation") // For addAction(int, CharSequence, PendingIntent)
+    @TargetApi(Build.VERSION_CODES.M) // For the Icon class.
+    protected static void addAction(Notification.Builder builder, Action action) {

[Peter Beverloo, 2016/02/10 12:29:37]

Could we give this a different name instead of overloading the other
addAction()?

[Michael van Ouwerkerk, 2016/02/10 17:18:12]

Sure, we do have many methods called addAction. Done.

+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M && action.iconBitmap != null) {
+            Icon icon = Icon.createWithBitmap(action.iconBitmap);
+            builder.addAction(
+                    new Notification.Action.Builder(icon, action.title, action.intent).build());
+        } else {
+            builder.addAction(action.iconId, action.title, action.intent);
+        }
+    }
 }