Fix infinite loop in GetInputMethod.

RWHVV shouldn't update ime if there is no inputmethod associated with the view.

BUG=none
TEST=none

Review URL: http://codereview.chromium.org/7976028

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@102225 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/renderer_host/render_widget_host_view_views.cc

@@ -271,14 +271,21 @@ void RenderWidgetHostViewViews::ImeUpdateTextInputState(
   // as true. We need to support "can_compose_inline=false" for PPAPI plugins
   // that may want to avoid drawing composition-text by themselves and pass
   // the responsibility to the browser.
-  DCHECK(GetInputMethod());
+
+  // This is async message and by the time the ipc arrived,
+  // RWHVV may be detached from Top level widget, in which case
+  // GetInputMethod may return NULL;
+  views::InputMethod* input_method = GetInputMethod();
+
   if (text_input_type_ != type) {
     text_input_type_ = type;
-    GetInputMethod()->OnTextInputTypeChanged(this);
+    if (input_method)
+      input_method->OnTextInputTypeChanged(this);
   }
   if (caret_bounds_ != caret_rect) {
     caret_bounds_ = caret_rect;
-    GetInputMethod()->OnCaretBoundsChanged(this);
+    if (input_method)
+      input_method->OnCaretBoundsChanged(this);
   }
 }
 

views/widget/widget.cc

@@ -622,7 +622,12 @@ InputMethod* Widget::GetInputMethod() {
     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;
   }
 }