Bug 1396951 - 4. Pass in GeckoView instance when sending a11y event; r=snorp

Pass in a `GeckoView` instance when sending a11y events so we're not
dependent on `GeckoAppShell.getLayerView()`. However, there's likely
more work to be done to make a11y work for any GeckoView.

MozReview-Commit-ID: DBeDOX5c3qY

--HG--
extra : rebase_source : 49d9a06ec90543c49d03f298a7d78ea54bbe0a58

mobile/android/base/java/org/mozilla/gecko/GeckoApp.java

@@ -673,7 +673,7 @@ public abstract class GeckoApp extends GeckoActivity
             GeckoAccessibility.updateAccessibilitySettings(this);
 
         } else if ("Accessibility:Event".equals(event)) {
-            GeckoAccessibility.sendAccessibilityEvent(message);
+            GeckoAccessibility.sendAccessibilityEvent(mLayerView, message);
 
         } else if ("Bookmark:Insert".equals(event)) {
             final BrowserDB db = BrowserDB.from(getProfile());

mobile/android/geckoview/src/main/java/org/mozilla/gecko/GeckoAccessibility.java

@@ -7,8 +7,6 @@ package org.mozilla.gecko;
 
 import org.json.JSONException;
 import org.json.JSONObject;
-import org.mozilla.gecko.EventDispatcher;
-import org.mozilla.gecko.gfx.LayerView;
 import org.mozilla.gecko.util.GeckoBundle;
 import org.mozilla.gecko.util.ThreadUtils;
 
@@ -110,7 +108,8 @@ public class GeckoAccessibility {
         return sEnabled;
     }
 
-    public static void sendAccessibilityEvent(final GeckoBundle message) {
+    public static void sendAccessibilityEvent(final GeckoView view,
+                                              final GeckoBundle message) {
         if (!sEnabled)
             return;
 
@@ -120,10 +119,11 @@ public class GeckoAccessibility {
             return;
         }
 
-        sendAccessibilityEvent(message, eventType);
+        sendAccessibilityEvent(view, message, eventType);
     }
 
-    public static void sendAccessibilityEvent(final GeckoBundle message, final int eventType) {
+    public static void sendAccessibilityEvent(final GeckoView view, final GeckoBundle message,
+                                              final int eventType) {
         if (!sEnabled)
             return;
 
@@ -148,10 +148,6 @@ public class GeckoAccessibility {
         } else {
             // In Jelly Bean we populate an AccessibilityNodeInfo with the minimal amount of data to have
             // it work with TalkBack.
-            final LayerView view = GeckoAppShell.getLayerView();
-            if (view == null)
-                return;
-
             if (sVirtualCursorNode == null) {
                 sVirtualCursorNode = AccessibilityNodeInfo.obtain(view, VIRTUAL_CURSOR_POSITION);
             }
@@ -266,7 +262,12 @@ public class GeckoAccessibility {
         AccessibilityNodeProvider mAccessibilityNodeProvider;
 
         @Override
-        public AccessibilityNodeProvider getAccessibilityNodeProvider(final View host) {
+        public AccessibilityNodeProvider getAccessibilityNodeProvider(final View hostView) {
+            if (!(hostView instanceof GeckoView)) {
+                return super.getAccessibilityNodeProvider(hostView);
+            }
+            final GeckoView host = (GeckoView) hostView;
+
             if (mAccessibilityNodeProvider == null)
                 // The accessibility node structure for web content consists of 3 LayerView child nodes:
                 // 1. VIRTUAL_ENTRY_POINT_BEFORE: Represents the entry point before the LayerView.
@@ -319,7 +320,7 @@ public class GeckoAccessibility {
                                 // The accessibility focus is permanently on the middle node, VIRTUAL_CURSOR_POSITION.
                                 // When we enter the view forward or backward we just ask Gecko to get focus, keeping the current position.
                                 if (virtualViewId == VIRTUAL_CURSOR_POSITION && sHoverEnter != null) {
-                                    GeckoAccessibility.sendAccessibilityEvent(sHoverEnter, AccessibilityEvent.TYPE_VIEW_ACCESSIBILITY_FOCUSED);
+                                    GeckoAccessibility.sendAccessibilityEvent(host, sHoverEnter, AccessibilityEvent.TYPE_VIEW_ACCESSIBILITY_FOCUSED);
                                 } else {
                                     final GeckoBundle data = new GeckoBundle(1);
                                     data.putBoolean("gainFocus", true);