Filter out datalist values for textarea field from renderer side.

components/autofill/content/renderer/autofill_agent.cc

Index: components/autofill/content/renderer/autofill_agent.cc
diff --git a/components/autofill/content/renderer/autofill_agent.cc b/components/autofill/content/renderer/autofill_agent.cc
index 7cd6e929273a6d6d9de2dd5d7931fe7d4a5b5e4c..c6c53a3e47bf4d34f3ce1d5df42aade1209e8649 100644
--- a/components/autofill/content/renderer/autofill_agent.cc
+++ b/components/autofill/content/renderer/autofill_agent.cc
@@ -640,24 +640,24 @@ void AutofillAgent::QueryAutofillSuggestions(
   gfx::RectF bounding_box_scaled =
       GetScaledBoundingBox(web_view_->pageScaleFactor(), &element_);
 
+  std::vector<base::string16> data_list_values;
+  std::vector<base::string16> data_list_labels;
   const WebInputElement* input_element = toWebInputElement(&element);
   if (input_element) {
     // Find the datalist values and send them to the browser process.
-    std::vector<base::string16> data_list_values;
-    std::vector<base::string16> data_list_labels;
     GetDataListSuggestions(*input_element,
                            datalist_only,
                            &data_list_values,
                            &data_list_labels);
     TrimStringVectorForIPC(&data_list_values);
     TrimStringVectorForIPC(&data_list_labels);
-
-    Send(new AutofillHostMsg_SetDataList(routing_id(),
-                                         data_list_values,
-                                         data_list_labels));
   }
 
   is_popup_possibly_visible_ = true;
+  Send(new AutofillHostMsg_SetDataList(routing_id(),
+                                       data_list_values,
+                                       data_list_labels));

[Ilya Sherman, 2014/04/29 20:29:30]

Aha!  This makes perfect sense -- we were showing stale values for the data
list.

It seems like it might make sense to just include the data list values and
labels as part of the AutofillHostMsg_QueryFormFieldAutofill message.  WDYT?

[ziran.sun, 2014/04/30 10:05:22]

It might make sense to send one message rather than two in this case. However, I
feel that this has restricted setDatalist call within queryFormFieldAutofill().
I'm thinking cases that we only want to update datalist values. The other things
is - inserting data_list_values and data_list_labels to
AutofillHostMsg_QueryFormFieldAutofill means that we also need to interact
IPC_messages to handle 7 arguments (at this moment it handles maximum 5
arguments).

Do let me know if I missed any key points though. Thanks!

+
   Send(new AutofillHostMsg_QueryFormFieldAutofill(routing_id(),
                                                   autofill_query_id_,
                                                   form,