Fix the double-tap to click gesture in touch accessibility mode.

chrome/browser/accessibility/accessibility_extension_api.cc

 // Copyright (c) 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.
 
 #include "chrome/browser/accessibility/accessibility_extension_api.h"
 
 #include <stddef.h>
 
 #include "base/json/json_writer.h"
 #include "base/strings/string_number_conversions.h"
@@ skipping 59 matching lines @@
     base::DictionaryValue* rect_value = NULL;
     EXTENSION_FUNCTION_VALIDATE(rect_values->GetDictionary(i, &rect_value));
     int left, top, width, height;
     EXTENSION_FUNCTION_VALIDATE(rect_value->GetInteger(kLeft, &left));
     EXTENSION_FUNCTION_VALIDATE(rect_value->GetInteger(kTop, &top));
     EXTENSION_FUNCTION_VALIDATE(rect_value->GetInteger(kWidth, &width));
     EXTENSION_FUNCTION_VALIDATE(rect_value->GetInteger(kHeight, &height));
     rects.push_back(gfx::Rect(left, top, width, height));
   }
 
+  // Move the visible focus ring to cover all of these rects.
   chromeos::AccessibilityFocusRingController::GetInstance()->SetFocusRing(
       rects);
+
+  // Also update the touch exploration controller so that synthesized
+  // touch events are anchored within the focused object.
+  if (!rects.empty()) {
+    chromeos::AccessibilityManager* manager =
+        chromeos::AccessibilityManager::Get();
+    manager->SetTouchAccessibilityAnchorPoint(rects[0].CenterPoint());
+  }
+
   return true;
 #endif  // defined(OS_CHROMEOS)
 
   error_ = kErrorNotSupported;
   return false;
 }
 
 ExtensionFunction::ResponseAction
 AccessibilityPrivateSetKeyboardListenerFunction::Run() {
   ChromeExtensionFunctionDetails details(this);
@@ skipping 19 matching lines @@
   } else {
     manager->SetKeyboardListenerExtensionId(std::string(),
                                             details.GetProfile());
     manager->set_keyboard_listener_capture(false);
   }
   return RespondNow(NoArguments());
 #endif  // defined OS_CHROMEOS
 
   return RespondNow(Error(kErrorNotSupported));
 }