Add way to get native VR UI information from Java

chrome/android/java/src/org/chromium/chrome/browser/vr_shell/VrShellImpl.java

Index: chrome/android/java/src/org/chromium/chrome/browser/vr_shell/VrShellImpl.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/vr_shell/VrShellImpl.java b/chrome/android/java/src/org/chromium/chrome/browser/vr_shell/VrShellImpl.java
index 777990dbddc45e396757af2cf842843b94fa8125..4274eee3cb6458f97ac622aebc69ca00c4c1bf3b 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/vr_shell/VrShellImpl.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/vr_shell/VrShellImpl.java
@@ -20,6 +20,9 @@ import android.widget.FrameLayout.LayoutParams;
 import com.google.vr.ndk.base.AndroidCompat;
 import com.google.vr.ndk.base.GvrLayout;
 
+import org.json.JSONException;
+import org.json.JSONObject;
+
 import org.chromium.base.CommandLine;
 import org.chromium.base.Log;
 import org.chromium.base.ThreadUtils;
@@ -57,6 +60,9 @@ import org.chromium.ui.base.WindowAndroid;
 import org.chromium.ui.display.DisplayAndroid;
 import org.chromium.ui.display.VirtualDisplayAndroid;
 
+import java.util.HashMap;
+import java.util.Iterator;
+
 /**
  * This view extends from GvrLayout which wraps a GLSurfaceView that renders VR shell.
  */
@@ -98,6 +104,8 @@ public class VrShellImpl
     private Surface mSurface;
     private View mPresentationView;
 
+    private OnUiElementInfoReplyCallback mUiElementInfoReplyCallback;
+
     // The tab that holds the main ContentViewCore.
     private Tab mTab;
     private NativePage mNativePage;
@@ -648,6 +656,36 @@ public class VrShellImpl
         mOnDispatchTouchEventForTesting = callback;
     }
 
+    @VisibleForTesting
+    public WebContents getUiContentsForTesting() {
+        return mUiContents;
+    }
+
+    /**
+     * Sends an asynchronous request for native UI element information.
+     * @param elementNames The names of all the elements you want info on
+     * @param onReply The runnable that will be run when native replies
+     */
+    @VisibleForTesting
+    public void requestUiElementInfoFromNativeForTesting(
+            String[] elementNames, OnUiElementInfoReplyCallback onReply) {
+        mUiElementInfoReplyCallback = onReply;
+        nativeRequestUiElementInfoForTesting(mNativeVrShell, elementNames);
+    }
+
+    @CalledByNative
+    public void replyToUiElementInfoRequestForTesting(String jsonString) throws JSONException {
+        JSONObject reply = new JSONObject(jsonString);
+        HashMap<String, JSONObject> uiElementInfo = new HashMap<String, JSONObject>();
+        for (Iterator<String> iter = reply.keys(); iter.hasNext();) {
+            String key = iter.next();
+            uiElementInfo.put(key, reply.optJSONObject(key));
+        }
+        if (mUiElementInfoReplyCallback != null) {
+            mUiElementInfoReplyCallback.onUiElementInfoReply(uiElementInfo);
+        }
+    }
+
     private native long nativeInit(WebContents uiWebContents, long nativeContentWindowAndroid,
             long nativeUiWindowAndroid, boolean forWebVR, VrShellDelegate delegate, long gvrApi,
             boolean reprojectedRendering);
@@ -674,4 +712,6 @@ public class VrShellImpl
     private native void nativeRestoreContentSurface(long nativeVrShell);
     private native void nativeSetHistoryButtonsEnabled(
             long nativeVrShell, boolean canGoBack, boolean canGoForward);
+    private native void nativeRequestUiElementInfoForTesting(
+            long nativeVrShell, String[] elementNames);
 }