[Home] Add lifecycle events and some tests

chrome/android/java/src/org/chromium/chrome/browser/widget/BottomSheetObserver.java

 // Copyright 2017 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.widget;
 
 /**
  * An interface for notifications about the state of the bottom sheet.
  */
 public interface BottomSheetObserver {
     /**
+     * A notification that the sheet has been opened, meaning the sheet is any height greater
+     * than its peeking state.
+     */
+    void onSheetOpened();
+
+    /**
+     * A notification that the sheet has closed, meaning the sheet has reached its peeking state.
+     */
+    void onSheetClosed();
+
+    /**
+     * A notification that the sheet has begun loading a URL.
+     * @param url The URL being loaded.
+     */
+    void onLoadUrl(String url);
+
+    /**
      * An event for when the sheet is transitioning from the peeking state to the half expanded
      * state. Once the sheet is outside the peek-half range, this event will no longer be
      * called.
      * @param transitionFraction The fraction of the way to the half expanded state that the
      *                           sheet is. This will be 0.0f when the sheet is peeking and 1.0f
      *                           when the sheet is half expanded.
      */
     void onTransitionPeekToHalf(float transitionFraction);
 }