Accept keyword by pressing space.

chrome/browser/autocomplete/autocomplete_edit_view_mac.mm

Index: chrome/browser/autocomplete/autocomplete_edit_view_mac.mm
diff --git a/chrome/browser/autocomplete/autocomplete_edit_view_mac.mm b/chrome/browser/autocomplete/autocomplete_edit_view_mac.mm
index 19040b5fbd5a7a9b6f4bc168107a9e1793b88939..1d9323d5c5b6a2f07b604d07a62f801e802cc912 100644
--- a/chrome/browser/autocomplete/autocomplete_edit_view_mac.mm
+++ b/chrome/browser/autocomplete/autocomplete_edit_view_mac.mm
@@ -649,8 +649,9 @@ bool AutocompleteEditViewMac::OnAfterPossibleChange() {
   const std::wstring new_text(GetText());
   const size_t length = new_text.length();
 
-  const bool selection_differs = !NSEqualRanges(new_selection,
-                                                selection_before_change_);
+  const bool selection_differs =
+      (new_selection.length || selection_before_change_.length) &&
+      !NSEqualRanges(new_selection, selection_before_change_);
   const bool at_end_of_edit = (length == new_selection.location);
   const bool text_differs = (new_text != text_before_change_) ||
       !NSEqualRanges(marked_range_before_change_, GetMarkedRange());
@@ -811,7 +812,7 @@ bool AutocompleteEditViewMac::OnDoCommandBySelector(SEL cmd) {
 
   if (cmd == @selector(insertTab:) ||
       cmd == @selector(insertTabIgnoringFieldEditor:)) {
-    if (model_->is_keyword_hint() && !model_->keyword().empty()) {
+    if (model_->is_keyword_hint()) {
       model_->AcceptKeyword();
       return true;
     }
@@ -942,8 +943,7 @@ void AutocompleteEditViewMac::OnPaste() {
   if ([editor shouldChangeTextInRange:selectedRange replacementString:s]) {
     // If this paste will be replacing all the text, record that, so
     // we can do different behaviors in such a case.
-    if (IsSelectAll())
-      model_->on_paste_replacing_all();
+    model_->OnPaste(IsSelectAll());
 
     // Force a Paste operation to trigger the text_changed code in
     // OnAfterPossibleChange(), even if identical contents are pasted