Address some TODOs for ChooserBubbleDelegate class

chrome/browser/ui/views/website_settings/chooser_bubble_ui_view.cc

Index: chrome/browser/ui/views/website_settings/chooser_bubble_ui_view.cc
diff --git a/chrome/browser/ui/views/website_settings/chooser_bubble_ui_view.cc b/chrome/browser/ui/views/website_settings/chooser_bubble_ui_view.cc
index 5d4d566b7ed5c9c1925bdf20f1d6203c0107087f..15d2bae5989996f7efe7e7107279442247705764 100644
--- a/chrome/browser/ui/views/website_settings/chooser_bubble_ui_view.cc
+++ b/chrome/browser/ui/views/website_settings/chooser_bubble_ui_view.cc
@@ -122,28 +122,22 @@ class ChooserTableModel : public ui::TableModel,
 
   // ui::TableModel:
   int RowCount() override {
-    const std::vector<base::string16>& device_names =
-        chooser_bubble_delegate_->GetOptions();
-    if (device_names.empty()) {
-      // Here it returns 1 when there is no device. In this case, the
-      // table view still needs to display a text message saying no
-      // devices found, so the number of rows is 1.
-      return 1;
-    } else {
-      return static_cast<int>(device_names.size());
-    }
+    size_t num_options = chooser_bubble_delegate_->NumOptions();
+    // Here it returns 1 when there is no device. In this case, the
+    // table view still needs to display a text message saying no
+    // devices found, so the number of rows is 1.

[Peter Kasting, 2016/01/04 21:02:52]

This comment is confusing.  How about:

When there are no devices, the table contains a message saying there are no
devices, so the number of rows is always at least 1.

[juncai, 2016/01/04 22:44:46]

Done.

+    return num_options == 0 ? 1 : static_cast<int>(num_options);

[Peter Kasting, 2016/01/04 21:02:52]

Same suggestion re: std::min().

[juncai, 2016/01/04 22:44:46]

Done.

   }
 
   // ui::TableModel:
   base::string16 GetText(int row, int column_id) override {

[Peter Kasting, 2016/01/04 21:02:52]

Same comments in this function as in the .mm file

[juncai, 2016/01/04 22:44:46]

Done.

-    const std::vector<base::string16>& device_names =
-        chooser_bubble_delegate_->GetOptions();
-    if (device_names.empty()) {
+    size_t num_options = chooser_bubble_delegate_->NumOptions();
+    if (num_options == 0) {
       DCHECK(row == 0);
       return l10n_util::GetStringUTF16(
           IDS_CHOOSER_BUBBLE_NO_DEVICES_FOUND_PROMPT);
-    } else if (row >= 0 && row < static_cast<int>(device_names.size())) {
-      return device_names[row];
+    } else if (row >= 0 && row < static_cast<int>(num_options)) {
+      return chooser_bubble_delegate_->GetOption(static_cast<size_t>(row));
     } else {
       NOTREACHED();
       return base::string16();
@@ -164,17 +158,17 @@ class ChooserTableModel : public ui::TableModel,
   }
 
   // ChooserOptions::Observer:
-  void OnOptionAdded(int index) override {
+  void OnOptionAdded(size_t index) override {
     if (observer_) {
-      observer_->OnItemsAdded(index, 1);
+      observer_->OnItemsAdded(static_cast<int>(index), 1);
       Update();
     }
   }
 
   // ChooserOptions::Observer:
-  void OnOptionRemoved(int index) override {
+  void OnOptionRemoved(size_t index) override {
     if (observer_) {
-      observer_->OnItemsRemoved(index, 1);
+      observer_->OnItemsRemoved(static_cast<int>(index), 1);
       Update();
     }
   }
@@ -182,7 +176,7 @@ class ChooserTableModel : public ui::TableModel,
   void Update() {
     views::TableView* table_view = static_cast<views::TableView*>(observer_);
 
-    if (chooser_bubble_delegate_->GetOptions().empty()) {
+    if (chooser_bubble_delegate_->NumOptions() == 0) {
       observer_->OnModelChanged();
       table_view->SetEnabled(false);
     } else {
@@ -232,7 +226,7 @@ ChooserBubbleUiViewDelegate::ChooserBubbleUiViewDelegate(
                   views::GridLayout::FILL, views::GridLayout::FILL,
                   kChooserPermissionBubbleWidth,
                   kChooserPermissionBubbleHeight);
-  if (chooser_bubble_delegate_->GetOptions().empty()) {
+  if (chooser_bubble_delegate_->NumOptions() == 0) {
     table_view_->SetEnabled(false);
   }