CollectedCookiesViews: don't show info for unfocused cookies

When the tab switches between allowed and blocked, cookie info
from the previous tab should no longer be shown.

BUG=649006

Review-Url: https://codereview.chromium.org/2361123002
Cr-Commit-Position: refs/heads/master@{#420693}

chrome/browser/ui/views/collected_cookies_views.cc

@@ -497,8 +497,10 @@ void CollectedCookiesViews::EnableControls() {
 }
 
 void CollectedCookiesViews::ShowCookieInfo() {
-  ui::TreeModelNode* node = allowed_cookies_tree_->GetSelectedNode();
-  if (!node)
+  ui::TreeModelNode* node = allowed_cookies_tree_->IsDrawn() ?
+                            allowed_cookies_tree_->GetSelectedNode() : nullptr;
+
+  if (!node && blocked_cookies_tree_->IsDrawn())
     node = blocked_cookies_tree_->GetSelectedNode();
 
   if (node) {