Remove the 2-level input method system & InputMethodBridge.

ui/views/controls/prefix_selector.cc

Index: ui/views/controls/prefix_selector.cc
diff --git a/ui/views/controls/prefix_selector.cc b/ui/views/controls/prefix_selector.cc
index f7e8f66fa833828cf983972e85d568a92445b2f4..b731b2b1d543b2d29716a9b9c97f8a8eae40bf6e 100644
--- a/ui/views/controls/prefix_selector.cc
+++ b/ui/views/controls/prefix_selector.cc
@@ -5,6 +5,7 @@
 #include "ui/views/controls/prefix_selector.h"
 
 #include "base/i18n/case_conversion.h"
+#include "ui/base/ime/input_method.h"
 #include "ui/base/ime/text_input_type.h"
 #include "ui/gfx/range/range.h"
 #include "ui/views/controls/prefix_delegate.h"
@@ -31,6 +32,9 @@ PrefixSelector::PrefixSelector(PrefixDelegate* delegate)
 }
 
 PrefixSelector::~PrefixSelector() {
+  ui::InputMethod* input_method = prefix_delegate_->GetInputMethod();

[sky, 2015/06/29 02:17:41]

How come PrefixSelector has to detach, but not attach? Doing this from the
destructor seems a bit risky given you don't know the state of the delegate. Can
the users of PrefixSelector detach?

[Shu Chen, 2015/06/29 02:56:34]

Done.

+  if (input_method)
+    input_method->DetachTextInputClient(this);
 }
 
 void PrefixSelector::OnViewBlur() {