Fix crash when drag moving URLs in chrome://settings/startup.

chrome/browser/custom_home_pages_table_model.cc

Index: chrome/browser/custom_home_pages_table_model.cc
diff --git a/chrome/browser/custom_home_pages_table_model.cc b/chrome/browser/custom_home_pages_table_model.cc
index 24607174635a0eab19ed825f5d08dfc3e82986d2..05f86cfeb705354e25704c0464531aa61e3427c6 100644
--- a/chrome/browser/custom_home_pages_table_model.cc
+++ b/chrome/browser/custom_home_pages_table_model.cc
@@ -96,9 +96,14 @@ void CustomHomePagesTableModel::SetURLs(const std::vector<GURL>& urls) {
  */
 void CustomHomePagesTableModel::MoveURLs(int insert_before,
                                          const std::vector<int>& index_list) {
-  DCHECK(!index_list.empty());
   DCHECK(insert_before >= 0 && insert_before <= RowCount());
 
+  // This is a bug. This should be a DCHECK, but under circumstances, the JS can
+  // get confused and pass us an empty list of selected indices to drag move.

[Dan Beam, 2013/10/14 18:08:07]

Are you sure it's the WebUI's fault? This can only be called from C++ as it's
not a message handling method.

+  // See http://crbug.com/302284.
+  if (index_list.empty())

[Dan Beam, 2013/10/14 18:08:07]

NOTREACHED();

+    return;
+
   // The range of elements that needs to be reshuffled is [ |first|, |last| ).
   int first = std::min(insert_before, index_list.front());
   int last = std::max(insert_before, index_list.back() + 1);