Add support for closing Android Shell instances from Java.

content/shell/android/java/src/org/chromium/content_shell/Shell.java

 // Copyright 2012 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.content_shell;
 
 import android.content.Context;
 import android.graphics.drawable.ClipDrawable;
 import android.text.TextUtils;
 import android.util.AttributeSet;
@@ skipping 31 matching lines @@
     };
 
     // TODO(jrg): a mContentView.destroy() call is needed, both upstream and downstream.
     private ContentView mContentView;
     private EditText mUrlTextView;
     private ImageButton mPrevButton;
     private ImageButton mNextButton;
 
     private ClipDrawable mProgressDrawable;
 
+    private long mNativeShell;
     private ContentViewRenderView mContentViewRenderView;
     private WindowAndroid mWindow;
 
     private boolean mLoading = false;
 
     /**
      * Constructor for inflating via XML.
      */
     public Shell(Context context, AttributeSet attrs) {
         super(context, attrs);
@@ skipping 11 matching lines @@
         } else {
             contentViewHolder.addView(contentViewRenderView,
                     new FrameLayout.LayoutParams(
                             FrameLayout.LayoutParams.MATCH_PARENT,
                             FrameLayout.LayoutParams.MATCH_PARENT));
         }
         mContentViewRenderView = contentViewRenderView;
     }
 
     /**
+     * Initializes the Shell for use.
+     *
+     * @param nativeShell The pointer to the native Shell object.
      * @param window The owning window for this shell.
      */
-    public void setWindow(WindowAndroid window) {
+    public void initialize(long nativeShell, WindowAndroid window) {
+        mNativeShell = nativeShell;
         mWindow = window;
     }
 
     /**
+     * Closes the shell and cleans up the native instance, which will handle destroying all
+     * dependencies.
+     */
+    public void close() {
+        if (mNativeShell == 0) return;
+        nativeCloseShell(mNativeShell);
+    }
+
+    @CalledByNative
+    private void onNativeDestroyed() {
+        mWindow = null;
+        mNativeShell = 0;
+        assert !mContentView.isAttachedToWindow()
+                : "Attempting to destroy the content view while attached to the view hierarchy.";
+        mContentView.destroy();
+    }
+
+    /**
+     * @return Whether the Shell has been destroyed.
+     * @see #onNativeDestroyed()
+     */
+    public boolean isDestroyed() {
+        return mNativeShell == 0;
+    }
+
+    /**
      * @return Whether or not the Shell is loading content.
      */
     public boolean isLoading() {
         return mLoading;
     }
 
     @Override
     protected void onFinishInflate() {
         super.onFinishInflate();
 
@@ skipping 135 matching lines @@
 
     private void setKeyboardVisibilityForUrl(boolean visible) {
         InputMethodManager imm = (InputMethodManager) getContext().getSystemService(
                 Context.INPUT_METHOD_SERVICE);
         if (visible) {
             imm.showSoftInput(mUrlTextView, InputMethodManager.SHOW_IMPLICIT);
         } else {
             imm.hideSoftInputFromWindow(mUrlTextView.getWindowToken(), 0);
         }
     }
+
+    private static native void nativeCloseShell(long shellPtr);
 }