Fix infinite loop in GetInputMethod.

views/widget/widget.cc

 // Copyright (c) 2011 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 "views/widget/widget.h"
 
 #include "base/logging.h"
 #include "base/message_loop.h"
 #include "base/utf_string_conversions.h"
 #include "ui/base/l10n/l10n_font_util.h"
@@ skipping 604 matching lines @@
   return toplevel_widget ? toplevel_widget->focus_manager_.get() : NULL;
 }
 
 InputMethod* Widget::GetInputMethod() {
   if (is_top_level()) {
     if (!input_method_.get())
       input_method_.reset(native_widget_->CreateInputMethod());
     return input_method_.get();
   } else {
     Widget* toplevel = GetTopLevelWidget();
-    return toplevel ? toplevel->GetInputMethod() : NULL;
+    // If GetTopLevelWidget() returns itself which is not toplevel,
+    // the widget is detached from toplevel widget.
+    // TODO(oshima): Fix GetTopLevelWidget() to return NULL
+    // if there is no toplevel. We probably need to add GetTopMostWidget()
+    // to replace some use cases.
+    return toplevel && toplevel != this ? toplevel->GetInputMethod() : NULL;
   }
 }
 
 void Widget::RunShellDrag(View* view, const ui::OSExchangeData& data,
                           int operation) {
   dragged_view_ = view;
   native_widget_->RunShellDrag(view, data, operation);
   // If the view is removed during the drag operation, dragged_view_ is set to
   // NULL.
   if (view && dragged_view_ == view) {
@@ skipping 537 matching lines @@
 
 ////////////////////////////////////////////////////////////////////////////////
 // internal::NativeWidgetPrivate, NativeWidget implementation:
 
 internal::NativeWidgetPrivate* NativeWidgetPrivate::AsNativeWidgetPrivate() {
   return this;
 }
 
 }  // namespace internal
 }  // namespace views