Hide (Android) NTP omnibox while in VR.

The NTP omnibox doesn't work in VR because we don't support keyboard for
Android Java UI elements. We also have a separate omnibox below the
content window in VR, so the one on the NTP is redundant.

Bug: 767988
Change-Id: I17fc2a81da20bac4b4effa279876a093c76ddad5
Reviewed-on: https://chromium-review.googlesource.com/899465Reviewed-by: David Trainor <dtrainor@chromium.org>
Commit-Queue: Michael Thiessen <mthiesse@chromium.org>
Cr-Commit-Position: refs/heads/master@{#534546}

chrome/android/java/src/org/chromium/chrome/browser/ntp/NewTabPageView.java

@@ -55,6 +55,7 @@ import org.chromium.chrome.browser.tab.Tab;
 import org.chromium.chrome.browser.util.FeatureUtilities;
 import org.chromium.chrome.browser.util.MathUtils;
 import org.chromium.chrome.browser.util.ViewUtils;
+import org.chromium.chrome.browser.vr_shell.VrShellDelegate;
 import org.chromium.chrome.browser.widget.displaystyle.UiConfig;
 import org.chromium.ui.base.DeviceFormFactor;
 
@@ -62,7 +63,8 @@ import org.chromium.ui.base.DeviceFormFactor;
  * The native new tab page, represented by some basic data such as title and url, and an Android
  * View that displays the page.
  */
-public class NewTabPageView extends FrameLayout implements TileGroup.Observer {
+public class NewTabPageView
+        extends FrameLayout implements TileGroup.Observer, VrShellDelegate.VrModeObserver {
     private static final String TAG = "NewTabPageView";
 
     private static final long SNAP_SCROLL_DELAY_MS = 30;
@@ -249,12 +251,6 @@ public class NewTabPageView extends FrameLayout implements TileGroup.Observer {
         mContextMenuManager = new ContextMenuManager(mManager.getNavigationDelegate(),
                 mRecyclerView::setTouchEnabled, closeContextMenuCallback);
         mTab.getWindowAndroid().addContextMenuCloseListener(mContextMenuManager);
-        manager.addDestructionObserver(new DestructionObserver() {
-            @Override
-            public void onDestroy() {
-                mTab.getWindowAndroid().removeContextMenuCloseListener(mContextMenuManager);
-            }
-        });
 
         Profile profile = Profile.getLastUsedProfile();
         OfflinePageBridge offlinePageBridge =
@@ -340,6 +336,16 @@ public class NewTabPageView extends FrameLayout implements TileGroup.Observer {
             }
         });
 
+        VrShellDelegate.registerVrModeObserver(this);
+        if (VrShellDelegate.isInVr()) onEnterVr();
+
+        manager.addDestructionObserver(new DestructionObserver() {
+            @Override
+            public void onDestroy() {
+                NewTabPageView.this.onDestroy();
+            }
+        });
+
         mInitialized = true;
 
         TraceEvent.end(TAG + ".initialize()");
@@ -1012,4 +1018,18 @@ public class NewTabPageView extends FrameLayout implements TileGroup.Observer {
         }
     }
 
+    @Override
+    public void onEnterVr() {
+        mSearchBoxView.setVisibility(GONE);
+    }
+
+    @Override
+    public void onExitVr() {
+        mSearchBoxView.setVisibility(VISIBLE);
+    }
+
+    private void onDestroy() {
+        mTab.getWindowAndroid().removeContextMenuCloseListener(mContextMenuManager);
+        VrShellDelegate.unregisterVrModeObserver(this);
+    }
 }

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

@@ -65,6 +65,8 @@ import java.lang.annotation.RetentionPolicy;
 import java.lang.ref.WeakReference;
 import java.lang.reflect.Constructor;
 import java.lang.reflect.InvocationTargetException;
+import java.util.ArrayList;
+import java.util.List;
 
 /**
  * Manages interactions with the VR Shell.
@@ -180,6 +182,23 @@ public class VrShellDelegate
     // Gets run when the user exits VR mode by clicking the 'x' button or system UI back button.
     private Runnable mCloseButtonListener;
 
+    private static final List<VrModeObserver> sVrModeObservers = new ArrayList<>();
+
+    /**
+     * Used to observe changes to whether Chrome is currently being viewed in VR.
+     */
+    public static interface VrModeObserver {
+        /**
+         * Called when Chrome enters VR rendering mode.
+         */
+        void onEnterVr();
+
+        /**
+         * Called when Chrome exits VR rendering mode.
+         */
+        void onExitVr();
+    }
+
     private static final class VrBroadcastReceiver extends BroadcastReceiver {
         private final WeakReference<ChromeActivity> mTargetActivity;
 
@@ -246,6 +265,24 @@ public class VrShellDelegate
         }
     }
 
+    /**
+     * Registers the given {@link VrModeObserver}.
+     *
+     * @param observer The VrModeObserver to register.
+     */
+    public static void registerVrModeObserver(VrModeObserver observer) {
+        sVrModeObservers.add(observer);
+    }
+
+    /**
+     * Unregisters the given {@link VrModeObserver}.
+     *
+     * @param observer The VrModeObserver to remove.
+     */
+    public static void unregisterVrModeObserver(VrModeObserver observer) {
+        sVrModeObservers.remove(observer);
+    }
+
     /**
      * See {@link Activity#onActivityResult}.
      */
@@ -874,6 +911,8 @@ public class VrShellDelegate
             }, EXPECT_DON_TIMEOUT_MS);
         }
         maybeSetPresentResult(true, donSuceeded);
+
+        for (VrModeObserver observer : sVrModeObservers) observer.onEnterVr();
     }
 
     private static void addBlackOverlayViewForActivity(ChromeActivity activity) {
@@ -1489,6 +1528,8 @@ public class VrShellDelegate
         // that we are exiting VR.
         callOnExitVrRequestListener(false);
         assert mOnExitVrRequestListener == null;
+
+        for (VrModeObserver observer : sVrModeObservers) observer.onExitVr();
     }
 
     private void callOnExitVrRequestListener(boolean success) {