Refine Views textfield state interaction, testing, and examples.

ui/views/controls/textfield/textfield.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 "ui/views/controls/textfield/textfield.h"
 
 #include <string>
 
 #include "base/command_line.h"
 #include "base/string_util.h"
@@ skipping 110 matching lines @@
 
 void Textfield::SetController(TextfieldController* controller) {
   controller_ = controller;
 }
 
 TextfieldController* Textfield::GetController() const {
   return controller_;
 }
 
 void Textfield::SetReadOnly(bool read_only) {
+  // Update read-only without changing the focusable state (or active, etc.).
   read_only_ = read_only;
-  set_focusable(!read_only);
   if (native_wrapper_) {
     native_wrapper_->UpdateReadOnly();
     native_wrapper_->UpdateTextColor();
     native_wrapper_->UpdateBackgroundColor();
   }
 }
 
 bool Textfield::IsObscured() const {
   return style_ & STYLE_OBSCURED;
 }
@@ skipping 458 matching lines @@
 NativeTextfieldWrapper* NativeTextfieldWrapper::CreateWrapper(
     Textfield* field) {
 #if defined(OS_WIN) && !defined(USE_AURA)
   if (!Textfield::IsViewsTextfieldEnabled())
     return new NativeTextfieldWin(field);
 #endif
   return new NativeTextfieldViews(field);
 }
 
 }  // namespace views