An edit for SetText needs to be merged with previous edit for omnibox.

views/controls/textfield/textfield_views_model.h

Index: views/controls/textfield/textfield_views_model.h
diff --git a/views/controls/textfield/textfield_views_model.h b/views/controls/textfield/textfield_views_model.h
index de7e5204cb4f286f67f977c0e23cdbc05bb32ec5..fd5a9da447766314274d661a44880d76e674e2db 100644
--- a/views/controls/textfield/textfield_views_model.h
+++ b/views/controls/textfield/textfield_views_model.h
@@ -34,6 +34,13 @@ class Edit;
 
 struct TextStyleRange;
 
+// C++ doesn't allow forward decl enum, so let's define here.
+enum MergeType {
+  DONT_MERGE,

[msw, 2011/06/02 10:16:42]

nit: rename DO_NOT_MERGE, the DONT contraction without its apostrophe is ugly.

[oshima, 2011/06/02 19:11:42]

Done.

+  MERGEABLE,
+  MERGE_WITH_PREVIOUS,
+};
+
 }  // namespace internal
 
 typedef std::vector<internal::TextStyleRange*> TextStyleRanges;
@@ -313,10 +320,13 @@ class TextfieldViewsModel {
 
   // Executes and records edit operations.
   void ExecuteAndRecordDelete(size_t from, size_t to, bool mergeable);
-  void ExecuteAndRecordReplace(const string16& text, bool mergeable);
-  void ExecuteAndRecordReplaceAt(const string16& text,
-                                 size_t at,
-                                 bool mergeable);
+  void ExecuteAndRecordReplaceSelection(internal::MergeType merge_type,
+                                        const string16& text);
+  void ExecuteAndRecordReplace(internal::MergeType merge_type,
+                               size_t old_cursor_pos,
+                               size_t new_cursor_pos,
+                               const string16& text,
+                               size_t new_text_start);
   void ExecuteAndRecordInsert(const string16& text, bool mergeable);
 
   // Adds or merge |edit| into edit history. Return true if the edit