Add Autofill preview support for <select> input fields

components/autofill/content/renderer/form_autofill_util.cc

Index: components/autofill/content/renderer/form_autofill_util.cc
diff --git a/components/autofill/content/renderer/form_autofill_util.cc b/components/autofill/content/renderer/form_autofill_util.cc
index 74d5b689e6c331114072f986ec49251dd89eecec..0e399b600258b940d34579941af1af9f74d5e9b0 100644
--- a/components/autofill/content/renderer/form_autofill_util.cc
+++ b/components/autofill/content/renderer/form_autofill_util.cc
@@ -570,9 +570,9 @@ void PreviewFormField(const FormFieldData& data,
   if (data.value.empty())
     return;
 
-  // Preview input and textarea fields. For input fields, excludes checkboxes
-  // and radio buttons, as there is no provision for setSuggestedCheckedValue
-  // in WebInputElement.
+  // Preview input, textarea and select fields. For input fields, excludes
+  // checkboxes and radio buttons, as there is no provision for
+  // setSuggestedCheckedValue in WebInputElement.
   WebInputElement* input_element = toWebInputElement(field);
   if (IsTextInput(input_element)) {
     // If the maxlength attribute contains a negative value, maxLength()
@@ -590,6 +590,12 @@ void PreviewFormField(const FormFieldData& data,
     WebTextAreaElement textarea = field->to<WebTextAreaElement>();
     textarea.setSuggestedValue(data.value);
     field->setAutofilled(true);
+  } else if (IsSelectElement(*field)) {
+    WebSelectElement select_element = field->to<WebSelectElement>();
+    // Check the original selected option value
+    select_element.setOriginalValue(select_element.value());

[Ilya Sherman, 2014/02/08 01:40:41]

This should not be necessary; the select element should keep track of this state
internally.

+    select_element.setSuggestedValue(data.value);
+    field->setAutofilled(true);
   }
 }
 
@@ -1058,9 +1064,11 @@ bool ClearPreviewedFormWithElement(const WebInputElement& element,
     // want to reset the auto-filled status for fields that were previewed.
     WebFormControlElement control_element = control_elements[i];
 
-    // Only text input and textarea elements can be previewed.
+    // Only text input, textarea and Select elements can be previewed.

[Ilya Sherman, 2014/02/08 01:40:41]

nit: "Select" -> "select"

     WebInputElement* input_element = toWebInputElement(&control_element);
-    if (!IsTextInput(input_element) && !IsTextAreaElement(control_element))
+    if (!IsTextInput(input_element) &&
+        !IsTextAreaElement(control_element) &&
+        !IsSelectElement(control_element))
       continue;
 
     // If the element is not auto-filled, we did not preview it,
@@ -1071,7 +1079,9 @@ bool ClearPreviewedFormWithElement(const WebInputElement& element,
     if ((IsTextInput(input_element) &&
          input_element->suggestedValue().isEmpty()) ||
         (IsTextAreaElement(control_element) &&
-         control_element.to<WebTextAreaElement>().suggestedValue().isEmpty()))
+         control_element.to<WebTextAreaElement>().suggestedValue().isEmpty()) ||
+        (IsSelectElement(control_element) &&
+         control_element.to<WebSelectElement>().suggestedValue().isEmpty()))
       continue;
 
     // Clear the suggested value. For the initiating node, also restore the
@@ -1099,6 +1109,19 @@ bool ClearPreviewedFormWithElement(const WebInputElement& element,
         control_element.setAutofilled(was_autofilled);
       else
         control_element.setAutofilled(false);
+    } else if (IsSelectElement(control_element)) {
+      WebSelectElement select_element = control_element.to<WebSelectElement>();
+      select_element.setSuggestedValue(WebString());
+      bool is_initiating_node = (element == select_element);
+      if (is_initiating_node)
+        control_element.setAutofilled(was_autofilled);
+      else
+        control_element.setAutofilled(false);

[Ilya Sherman, 2014/02/08 01:40:41]

There's no need for handling the case where is_initiating_node is set to true,
because it's impossible to initiate Autofill from a <select> element.

+
+      // Set selected option back to the original one. Ideally this should
+      // happen right in the end of PreviewForm() but doing so will overwrite
+      // the preview value.
+      select_element.setValue(WebString(select_element.originalValue()));

[Ilya Sherman, 2014/02/08 01:40:41]

This should not be necessary; the <select> element should keep track of this
state internally.

     }
   }