Refactoring the ownership of ui::InputMethod.

ui/views/ime/input_method_bridge.cc

Index: ui/views/ime/input_method_bridge.cc
diff --git a/ui/views/ime/input_method_bridge.cc b/ui/views/ime/input_method_bridge.cc
index cb7860e8eab28f1d9283b128cefdde9d1adab92a..88ceec7d5c90938ecc4a40d6ef8a880878370f25 100644
--- a/ui/views/ime/input_method_bridge.cc
+++ b/ui/views/ime/input_method_bridge.cc
@@ -81,7 +81,8 @@ InputMethodBridge::~InputMethodBridge() {
 }
 
 void InputMethodBridge::OnFocus() {
-  DCHECK(host_);
+  if (!host_)  // |host_| could be NULL after OnInputMethodDestroyed.
+    return;
 
   // Direct the shared IME to send TextInputClient messages to |this| object.
   if (shared_input_method_ || !host_->GetTextInputClient())
@@ -96,7 +97,8 @@ void InputMethodBridge::OnFocus() {
 }
 
 void InputMethodBridge::OnBlur() {
-  DCHECK(host_);
+  if (!host_)  // |host_| could be NULL after OnInputMethodDestroyed.
+    return;
 
   if (HasCompositionText()) {
     ConfirmCompositionText();