VR: Stop injecting Views for UI elements when browsing is not enabled

Do not add Views for Clank UI in VR when VrBrowsing is not enabled.

BUG=779126

Change-Id: Iecd228366cd3f56d74ca5944b47b70b78cb7d14c
Reviewed-on: https://chromium-review.googlesource.com/902003Reviewed-by: Michael Thiessen <mthiesse@chromium.org>
Commit-Queue: Amirhossein Simjour <asimjour@chromium.org>
Cr-Commit-Position: refs/heads/master@{#534449}

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

@@ -162,19 +162,7 @@ public class VrShellImpl extends GvrLayout implements VrShell, SurfaceHolder.Cal
 
         getUiLayout().setCloseButtonListener(mDelegate.getVrCloseButtonListener());
 
-        if (ChromeFeatureList.isEnabled(ChromeFeatureList.VR_BROWSING_NATIVE_ANDROID_UI)) {
-            mNonVrModalDialogManager = mActivity.getModalDialogManager();
-            mNonVrModalDialogManager.cancelAllDialogs();
-            mActivity.setModalDialogManager(new ModalDialogManager(
-                    new VrModalPresenter(this), ModalDialogManager.APP_MODAL));
-        }
-        ViewGroup decor = (ViewGroup) mActivity.getWindow().getDecorView();
-        mUiView = new FrameLayout(decor.getContext());
-        LayoutParams params = new FrameLayout.LayoutParams(
-                ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT);
-        decor.addView(mUiView, params);
-        mVrUiViewContainer = new VrViewContainer(mActivity);
-        mUiView.addView(mVrUiViewContainer);
+        if (mVrBrowsingEnabled) injectVrHostedUiView();
 
         mTabRedirectHandler = new TabRedirectHandler(mActivity) {
             @Override
@@ -281,6 +269,22 @@ public class VrShellImpl extends GvrLayout implements VrShell, SurfaceHolder.Cal
         mNonVrViews = viewContainer;
     }
 
+    private void injectVrHostedUiView() {
+        if (!ChromeFeatureList.isEnabled(ChromeFeatureList.VR_BROWSING_NATIVE_ANDROID_UI)) return;
+        mNonVrModalDialogManager = mActivity.getModalDialogManager();
+        mNonVrModalDialogManager.cancelAllDialogs();
+        mActivity.setModalDialogManager(
+                new ModalDialogManager(new VrModalPresenter(this), ModalDialogManager.APP_MODAL));
+
+        ViewGroup decor = (ViewGroup) mActivity.getWindow().getDecorView();
+        mUiView = new FrameLayout(decor.getContext());
+        LayoutParams params = new FrameLayout.LayoutParams(
+                ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT);
+        decor.addView(mUiView, params);
+        mVrUiViewContainer = new VrViewContainer(mActivity);
+        mUiView.addView(mVrUiViewContainer);
+    }
+
     private void removeVrRootView() {
         ViewGroup parent = (ViewGroup) mNonVrViews.getParent();
         assert mNonVrViews.getChildCount() == 1;
@@ -530,7 +534,7 @@ public class VrShellImpl extends GvrLayout implements VrShell, SurfaceHolder.Cal
 
     @CalledByNative
     public void dialogSurfaceCreated(Surface surface) {
-        mVrUiViewContainer.setSurface(surface);
+        if (mVrBrowsingEnabled) mVrUiViewContainer.setSurface(surface);
     }
 
     @Override