Refactor contextual search's panel host and scene layer

chrome/android/javatests/src/org/chromium/chrome/browser/contextualsearch/ContextualSearchEventFilterTest.java

Index: chrome/android/javatests/src/org/chromium/chrome/browser/contextualsearch/ContextualSearchEventFilterTest.java
diff --git a/chrome/android/javatests/src/org/chromium/chrome/browser/contextualsearch/ContextualSearchEventFilterTest.java b/chrome/android/javatests/src/org/chromium/chrome/browser/contextualsearch/ContextualSearchEventFilterTest.java
index 304c8e805ca945efc9c09bb6dda443e21c739ad3..95bc4cc1220b4b15243b5cd0f72e539543a935d8 100644
--- a/chrome/android/javatests/src/org/chromium/chrome/browser/contextualsearch/ContextualSearchEventFilterTest.java
+++ b/chrome/android/javatests/src/org/chromium/chrome/browser/contextualsearch/ContextualSearchEventFilterTest.java
@@ -20,6 +20,7 @@ import org.chromium.chrome.browser.compositor.layouts.LayoutUpdateHost;
 import org.chromium.chrome.browser.compositor.layouts.eventfilter.ContextualSearchEventFilter;
 import org.chromium.chrome.browser.compositor.layouts.eventfilter.EventFilterHost;
 import org.chromium.chrome.browser.compositor.layouts.eventfilter.GestureHandler;
+import org.chromium.chrome.browser.compositor.scene_layer.ContextualSearchSceneLayer;
 
 /**
  * Class responsible for testing the ContextualSearchEventFilter.
@@ -139,6 +140,11 @@ public class ContextualSearchEventFilterTest extends InstrumentationTestCase
             return new MockOverlayPanelContent();
         }
 
+        @Override
+        protected ContextualSearchSceneLayer createNewContextualSearchSceneLayer() {
+            return null;
+        }
+
         /**
          * Override creation and destruction of the ContentViewCore as they rely on native methods.
          */