Helper functions for tracking stale TabContentsDelegate's.

content/browser/tab_contents/tab_contents_delegate.cc

Index: content/browser/tab_contents/tab_contents_delegate.cc
diff --git a/content/browser/tab_contents/tab_contents_delegate.cc b/content/browser/tab_contents/tab_contents_delegate.cc
index df709a7f3549d644f105f444c44fa39572fa83ec..acc201ba98d3de7ca6da6166ea6e23eddf5ed68a 100644
--- a/content/browser/tab_contents/tab_contents_delegate.cc
+++ b/content/browser/tab_contents/tab_contents_delegate.cc
@@ -5,11 +5,22 @@
 #include "content/browser/tab_contents/tab_contents_delegate.h"
 
 #include "base/compiler_specific.h"
+#include "base/logging.h"
 #include "base/memory/singleton.h"
 #include "content/browser/javascript_dialogs.h"
 #include "content/common/url_constants.h"
 #include "ui/gfx/rect.h"
 
+void TabContentsDelegate::Attach(TabContents* tab_contents) {
+  CHECK(attached_contents_.find(tab_contents) == attached_contents_.end());
+  attached_contents_.insert(tab_contents);
+}
+
+void TabContentsDelegate::Detach(TabContents* tab_contents) {
+  CHECK(attached_contents_.find(tab_contents) != attached_contents_.end());
+  attached_contents_.erase(tab_contents);
+}
+
 std::string TabContentsDelegate::GetNavigationHeaders(const GURL& url) {
   return std::string();
 }
@@ -238,4 +249,5 @@ TabContentsDelegate::GetJavaScriptDialogCreator() {
 }
 
 TabContentsDelegate::~TabContentsDelegate() {
+  CHECK(attached_contents_.empty());
 }