Fix ibus-m17n crash due to wrong parameter from Chrome.

ui/base/ime/input_method_ibus.cc

Index: ui/base/ime/input_method_ibus.cc
diff --git a/ui/base/ime/input_method_ibus.cc b/ui/base/ime/input_method_ibus.cc
index cce1f3df04ca479ac372ea4447e5a0e11598b184..9bbee01cc7e3ef959300dbb778ace3f4d1b1bf62 100644
--- a/ui/base/ime/input_method_ibus.cc
+++ b/ui/base/ime/input_method_ibus.cc
@@ -267,13 +267,13 @@ void InputMethodIBus::OnCaretBoundsChanged(const TextInputClient* client) {
   previous_selection_range_ = selection_range;
   previous_surrounding_text_ = surrounding_text;
 
-  // In the original meaning of SetSurroundingText is not just selection text,
-  // but currently there are no way to retrieve surrounding text in
-  // TextInputClient.
+  // Here SetSurroundingText accepts relative position of |surrounding_text|, so
+  // we have to convert |selection_range| from node coordinates to
+  // |surrounding_text| coordinates.
   GetInputContextClient()->SetSurroundingText(
       UTF16ToUTF8(surrounding_text),
-      selection_range.start(), /* cursor position. */
-      selection_range.end()); /* selection anchor position. */
+      selection_range.start() - text_range.start(),
+      selection_range.end() - text_range.start());
 }
 
 void InputMethodIBus::CancelComposition(const TextInputClient* client) {