Quickly close tabs/window with long-running unload handlers.

content/browser/web_contents/web_contents_impl.cc

Index: content/browser/web_contents/web_contents_impl.cc
diff --git a/content/browser/web_contents/web_contents_impl.cc b/content/browser/web_contents/web_contents_impl.cc
index ea88e0c8b8a00743fe05980826b621c3e951308c..6c8f28a2162495cb116ff7f6110830f190959481 100644
--- a/content/browser/web_contents/web_contents_impl.cc
+++ b/content/browser/web_contents/web_contents_impl.cc
@@ -8,6 +8,7 @@
 
 #include "base/command_line.h"
 #include "base/lazy_instance.h"
+#include "base/logging.h"
 #include "base/metrics/histogram.h"
 #include "base/metrics/stats_counters.h"
 #include "base/string16.h"
@@ -398,11 +399,18 @@ WebContentsImpl::~WebContentsImpl() {
   // OnCloseStarted isn't called in unit tests.
   if (!close_start_time_.is_null()) {
     base::TimeTicks now = base::TimeTicks::Now();
+    base::TimeDelta close_time = now - close_start_time_;
+    UMA_HISTOGRAM_TIMES("Tab.Close", close_time);
+
     base::TimeTicks unload_start_time = close_start_time_;
+    base::TimeTicks unload_end_time = now;
     if (!before_unload_end_time_.is_null())
       unload_start_time = before_unload_end_time_;
-    UMA_HISTOGRAM_TIMES("Tab.Close", now - close_start_time_);
-    UMA_HISTOGRAM_TIMES("Tab.Close.UnloadTime", now - unload_start_time);
+    if (!unload_detached_start_time_.is_null())
+      unload_end_time = unload_detached_start_time_;
+    base::TimeDelta unload_time = unload_end_time - unload_start_time;
+    UMA_HISTOGRAM_TIMES("Tab.Close.UnloadTime", unload_time);
+
   }
 
   FOR_EACH_OBSERVER(WebContentsObserver,
@@ -1930,6 +1938,21 @@ void WebContentsImpl::OnCloseStarted() {
     close_start_time_ = base::TimeTicks::Now();
 }
 
+void WebContentsImpl::OnCloseCanceled() {
+  close_start_time_ = base::TimeTicks();
+  before_unload_end_time_ = base::TimeTicks();
+  unload_detached_start_time_ = base::TimeTicks();
+}
+
+void WebContentsImpl::OnUnloadStarted() {
+  before_unload_end_time_ = base::TimeTicks::Now();
+}
+
+void WebContentsImpl::OnUnloadDetachedStarted() {
+  if (unload_detached_start_time_.is_null())
+    unload_detached_start_time_ = base::TimeTicks::Now();
+}
+
 void WebContentsImpl::DragSourceEndedAt(int client_x, int client_y,
     int screen_x, int screen_y, WebKit::WebDragOperation operation) {
   if (browser_plugin_embedder_.get())
@@ -3583,9 +3606,7 @@ void WebContentsImpl::OnDialogClosed(RenderViewHost* rvh,
     // spinning, since we forced it to start spinning in Navigate.
     DidStopLoading(rvh);
     controller_.DiscardNonCommittedEntries();
-
-    close_start_time_ = base::TimeTicks();
-    before_unload_end_time_ = base::TimeTicks();
+    OnCloseCanceled();
   }
   is_showing_before_unload_dialog_ = false;
   static_cast<RenderViewHostImpl*>(