Remove disable warnings compile flag in safebrowsing component, and fix some type win64 type errors…

components/safe_browsing/renderer/threat_dom_details.cc

Index: components/safe_browsing/renderer/threat_dom_details.cc
diff --git a/components/safe_browsing/renderer/threat_dom_details.cc b/components/safe_browsing/renderer/threat_dom_details.cc
index 90d70e48ba3d96ade60a5f4028d738d1db8d7aae..f6e1abefe0ee138a5d4f6c5c86804998c23a3421 100644
--- a/components/safe_browsing/renderer/threat_dom_details.cc
+++ b/components/safe_browsing/renderer/threat_dom_details.cc
@@ -109,7 +109,7 @@ SafeBrowsingHostMsg_ThreatDOMDetails_Node* GetNodeForElement(
     const safe_browsing::ElementToNodeMap& element_to_node_map,
     std::vector<SafeBrowsingHostMsg_ThreatDOMDetails_Node>* resources) {
   DCHECK(element_to_node_map.count(element) > 0);
-  int resource_index = element_to_node_map.at(element);
+  size_t resource_index = element_to_node_map.at(element);
   return &(resources->at(resource_index));
 }
 
@@ -171,7 +171,7 @@ void HandleElement(
   // Update the ID mapping. First generate the ID for the current node.
   // Then, if its parent is available, set the current node's parent ID, and
   // also update the parent's children with the current node's ID.
-  const size_t child_id = element_to_node_map->size() + 1;
+  const int child_id = static_cast<int>(element_to_node_map->size()) + 1;

[Nathan Parker, 2017/03/22 21:12:56]

Why cast to int?  I'm not confident I know which is safer, since an overflow
here would turn negative, which may have bad effects.

[lpz, 2017/03/23 15:37:32]

The alternative would be to keep size_t here but then the IPC message fields
will have to be changed to size_t, which is a blacklisted IPC type apparently. I
could cast to ints before setting the IPC fields, but seems easier to do it
here.

Note also that the size of this map is capped by kMaxNodes, which is currently
at 500, so at least some control from overflows.

   child_node.node_id = child_id;
   blink::WebNode cur_parent_element = element.parentNode();
   while (!cur_parent_element.isNull()) {