Defer enabling native accessibility until it's used.

content/public/android/java/src/org/chromium/content/browser/ContentViewCore.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.browser;
 
 import android.app.Activity;
 import android.content.ContentResolver;
 import android.content.Context;
 import android.content.pm.ActivityInfo;
@@ skipping 385 matching lines @@
     private boolean mSelectionEditable;
     private ActionMode mActionMode;
     private boolean mUnselectAllOnActionModeDismiss;
 
     // Delegate that will handle GET downloads, and be notified of completion of POST downloads.
     private ContentViewDownloadDelegate mDownloadDelegate;
 
     // The AccessibilityInjector that handles loading Accessibility scripts into the web page.
     private AccessibilityInjector mAccessibilityInjector;
 
+    // Whether native accessibility, i.e. without any script injection, is allowed.
+    private boolean mNativeAccessibilityAllowed;
+
+    // Whether native accessibility, i.e. without any script injection, has been enabled.
+    private boolean mNativeAccessibilityEnabled;
+
     // Handles native accessibility, i.e. without any script injection.
     private BrowserAccessibilityManager mBrowserAccessibilityManager;
 
     // System accessibility service.
     private final AccessibilityManager mAccessibilityManager;
 
     // Allows us to dynamically respond when the accessibility script injection flag changes.
     private ContentObserver mAccessibilityScriptInjectionObserver;
 
     // Temporary notification to tell onSizeChanged to focus a form element,
@@ skipping 2346 matching lines @@
      * @return This view's BrowserAccessibilityManager.
      */
     public BrowserAccessibilityManager getBrowserAccessibilityManager() {
         return mBrowserAccessibilityManager;
     }
 
     /**
      * If native accessibility (not script injection) is enabled, and if this is
      * running on JellyBean or later, returns an AccessibilityNodeProvider that
      * implements native accessibility for this view. Returns null otherwise.
+     * Lazily initializes native accessibility here if it's allowed.
      * @return The AccessibilityNodeProvider, if available, or null otherwise.
      */
     public AccessibilityNodeProvider getAccessibilityNodeProvider() {
         if (mBrowserAccessibilityManager != null) {
             return mBrowserAccessibilityManager.getAccessibilityNodeProvider();
-        } else {
-            return null;
         }
+
+        if (mNativeAccessibilityAllowed &&
+                !mNativeAccessibilityEnabled &&
+                mNativeContentViewCore != 0 &&
+                Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {
+            mNativeAccessibilityEnabled = true;
+            nativeSetAccessibilityEnabled(mNativeContentViewCore, true);
+        }
+
+        return null;
     }
 
     /**
      * @see View#onInitializeAccessibilityNodeInfo(AccessibilityNodeInfo)
      */
     public void onInitializeAccessibilityNodeInfo(AccessibilityNodeInfo info) {
         // Note: this is only used by the script-injecting accessibility code.
         mAccessibilityInjector.onInitializeAccessibilityNodeInfo(info);
     }
 
@@ skipping 66 matching lines @@
      * Returns whether or not accessibility injection is being used.
      */
     public boolean isInjectingAccessibilityScript() {
         return mAccessibilityInjector.accessibilityIsAvailable();
     }
 
     /**
      * Turns browser accessibility on or off.
      * If |state| is |false|, this turns off both native and injected accessibility.
      * Otherwise, if accessibility script injection is enabled, this will enable the injected
-     * accessibility scripts, and if it is disabled this will enable the native accessibility.
+     * accessibility scripts. Native accessibility is enabled on demand.
      */
     public void setAccessibilityState(boolean state) {
-        boolean injectedAccessibility = false;
-        boolean nativeAccessibility = false;
-        if (state) {
-            if (isDeviceAccessibilityScriptInjectionEnabled()) {
-                injectedAccessibility = true;
-            } else {
-                nativeAccessibility = true;
-            }
+        if (!state) {
+            setInjectedAccessibility(false);
+            return;
         }
-        setInjectedAccessibility(injectedAccessibility);
-        setNativeAccessibilityState(nativeAccessibility);
+
+        if (isDeviceAccessibilityScriptInjectionEnabled()) {
+            setInjectedAccessibility(true);
+            return;
+        }
+
+        mNativeAccessibilityAllowed = true;
     }
 
     /**
-     * Enable or disable native accessibility features.
-     */
-    public void setNativeAccessibilityState(boolean enabled) {
-        if (mNativeContentViewCore == 0) return;
-        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {
-            nativeSetAccessibilityEnabled(mNativeContentViewCore, enabled);
-        }
-    }
-
-    /**
      * Enable or disable injected accessibility features
      */
     public void setInjectedAccessibility(boolean enabled) {
         mAccessibilityInjector.addOrRemoveAccessibilityApisIfNecessary();
         mAccessibilityInjector.setScriptEnabled(enabled);
     }
 
     /**
      * Stop any TTS notifications that are currently going on.
      */
@@ skipping 287 matching lines @@
 
     private native void nativeAttachExternalVideoSurface(
             int nativeContentViewCoreImpl, int playerId, Surface surface);
 
     private native void nativeDetachExternalVideoSurface(
             int nativeContentViewCoreImpl, int playerId);
 
     private native void nativeSetAccessibilityEnabled(
             int nativeContentViewCoreImpl, boolean enabled);
 }