Magnifier needs to follow the focus of the textfield.

ui/base/ime/input_method_base.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/base/ime/input_method_base.h"
 
 #include "base/bind.h"
 #include "base/logging.h"
 #include "base/message_loop/message_loop.h"
 #include "ui/base/ime/input_method_delegate.h"
@@ skipping 108 matching lines @@
   return delegate_->DispatchKeyEventPostIME(event);
 }
 
 void InputMethodBase::NotifyTextInputStateChanged(
     const TextInputClient* client) {
   FOR_EACH_OBSERVER(InputMethodObserver,
                     observer_list_,
                     OnTextInputStateChanged(client));
 }
 
+void InputMethodBase::NotifyTextInputCaretBoundsChanged(
+    const TextInputClient* client) {
+  FOR_EACH_OBSERVER(
+      InputMethodObserver, observer_list_, OnCaretBoundsChanged(client));
+}
+
 void InputMethodBase::SetFocusedTextInputClientInternal(
     TextInputClient* client) {
   if (switches::IsTextInputFocusManagerEnabled())
     return;
 
   TextInputClient* old = text_input_client_;
   if (old == client)
     return;
   OnWillChangeFocusedClient(old, client);
   text_input_client_ = client;  // NULL allowed.
@@ skipping 29 matching lines @@
   if (TextInputClient* text_input_client = GetTextInputClient())
     text_input_client->OnCandidateWindowUpdated();
 }
 
 void InputMethodBase::CandidateWindowHiddenCallback() {
   if (TextInputClient* text_input_client = GetTextInputClient())
     text_input_client->OnCandidateWindowHidden();
 }
 
 }  // namespace ui