[Mac] Delay TabContents::Close() when event-tracking.

chrome/browser/tab_contents/tab_contents.cc

Index: chrome/browser/tab_contents/tab_contents.cc
diff --git a/chrome/browser/tab_contents/tab_contents.cc b/chrome/browser/tab_contents/tab_contents.cc
index e72df68642ed11783ebd319c349bff635b744355..35e9b80b6c689576472310fee6ab286dd69ee23b 100644
--- a/chrome/browser/tab_contents/tab_contents.cc
+++ b/chrome/browser/tab_contents/tab_contents.cc
@@ -2179,6 +2179,21 @@ void TabContents::UpdateInspectorSettings(const std::string& raw_settings) {
 }
 
 void TabContents::Close(RenderViewHost* rvh) {
+  // The UI may be in an event-tracking loop, such as between the
+  // mouse-down and mouse-up in text selection or a button click.
+  // Defer the close until after tracking is complete, so that we
+  // don't free objects out from under the UI.
+  // TODO(shess): This could probably be integrated with the
+  // IsDoingDrag() test below.  Punting for now because I need more
+  // research to understand how this impacts platforms other than Mac.
+  // TODO(shess): This could get more fine-grained.  For instance,
+  // closing a tab in another window while selecting text in the
+  // current window's Omnibox should be just fine.
+  if (view()->IsEventTracking()) {
+    view()->CloseTabAfterEventTracking();
+    return;
+  }
+
   // If we close the tab while we're in the middle of a drag, we'll crash.
   // Instead, cancel the drag and close it as soon as the drag ends.
   if (view()->IsDoingDrag()) {