permissionrequest API for guest Download.

content/browser/browser_plugin/browser_plugin_guest.cc

Index: content/browser/browser_plugin/browser_plugin_guest.cc
diff --git a/content/browser/browser_plugin/browser_plugin_guest.cc b/content/browser/browser_plugin/browser_plugin_guest.cc
index 973408fbd476f1fa1a1d651c24368d9a7ca8a06c..20215f20c5bda8b458d635dcb814138ac33cf163 100644
--- a/content/browser/browser_plugin/browser_plugin_guest.cc
+++ b/content/browser/browser_plugin/browser_plugin_guest.cc
@@ -310,13 +310,36 @@ void BrowserPluginGuest::AddNewContents(WebContents* source,
 bool BrowserPluginGuest::CanDownload(RenderViewHost* render_view_host,
                                     int request_id,
                                     const std::string& request_method) {
-  // TODO(fsamuel): We disable downloads in guests for now, but we will later
-  // expose API to allow embedders to handle them.
-  // Note: it seems content_shell ignores this. This should be fixed
-  // for debugging and test purposes.
+  // We can only decide whether a guest can download or not through async API,
+  // see CanDownloadAsync().
+  NOTREACHED();
   return false;
 }
 
+void BrowserPluginGuest::CanDownloadAsync(
+    RenderViewHost* render_view_host,
+    int download_request_id,
+    const std::string& request_method,
+    const base::Callback<void(bool)>& callback) {
+  if (download_request_callback_map_.size() >=
+          kNumMaxOutstandingPermissionRequests) {
+    // Deny the download request.
+    callback.Run(false);
+    return;
+  }
+
+  int request_id = next_permission_request_id_++;
+  download_request_callback_map_[request_id] = callback;
+
+  base::DictionaryValue request_info;
+  request_info.Set(browser_plugin::kRequestMethod,
+                   base::Value::CreateStringValue(request_method));
+
+  SendMessageToEmbedder(
+      new BrowserPluginMsg_RequestPermission(instance_id(),
+          BrowserPluginPermissionTypeDownload, request_id, request_info));
+}
+
 bool BrowserPluginGuest::HandleContextMenu(
     const ContextMenuParams& params) {
   // TODO(fsamuel): We have a do nothing context menu handler for now until
@@ -945,6 +968,9 @@ void BrowserPluginGuest::OnRespondPermission(
     int request_id,
     bool should_allow) {
   switch (permission_type) {
+    case BrowserPluginPermissionTypeDownload:
+      OnRespondPermissionDownload(request_id, should_allow);
+      break;
     case BrowserPluginPermissionTypeGeolocation:
       OnRespondPermissionGeolocation(request_id, should_allow);
       break;
@@ -1157,6 +1183,20 @@ void BrowserPluginGuest::OnUpdateRect(
       new BrowserPluginMsg_UpdateRect(instance_id(), relay_params));
 }
 
+void BrowserPluginGuest::OnRespondPermissionDownload(int request_id,
+                                                     bool should_allow) {
+  DownloadRequestMap::iterator download_request_iter =
+      download_request_callback_map_.find(request_id);
+  if (download_request_iter == download_request_callback_map_.end()) {
+    LOG(INFO) << "Not a valid request ID.";
+    return;
+  }
+
+  const base::Callback<void(bool)>& can_download_callback =
+    download_request_iter->second;
+  can_download_callback.Run(should_allow);
+}
+
 void BrowserPluginGuest::OnRespondPermissionGeolocation(
     int request_id, bool should_allow) {
   if (should_allow && embedder_web_contents_) {