Upstream oodles of Chrome for Android code into Chromium.

chrome/android/java_staging/src/org/chromium/chrome/browser/contextualsearch/ContextualSearchObserver.java

+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.chrome.browser.contextualsearch;
+
+import org.chromium.chrome.browser.gsa.GSAContextDisplaySelection;
+
+import javax.annotation.Nullable;
+
+/**
+ * An interface to be notified when contextual searches are performed or no longer active.
+ */
+public interface ContextualSearchObserver {
+    /**
+     * Notifies that a contextual search was performed, and provides the selection context if
+     * the feature is fully enabled (and {@code null} otherwise).
+     * NOTE: this context data can be quite privacy-sensitive because it contains text from the
+     * page being viewed by the user, which may include sensitive or personal information.
+     * Clients must follow standard privacy policy before logging or transmitting this information.
+     * @param selectionContext The selection and context used for the Contextual Search, or
+     *        {@code null} if the feature has not yet been fully enabled.
+     */
+    void onShowContextualSearch(@Nullable GSAContextDisplaySelection selectionContext);
+
+    /**
+     * Notifies that a contextual search is no longer in effect, and the results are no longer
+     * available in the UX.
+     */
+    void onHideContextualSearch();
+}