Make sure RenderWidgetHostViewCocoa doesn't disappear inside of -keyEvent:

chrome/browser/renderer_host/render_widget_host_view_mac.mm

Index: chrome/browser/renderer_host/render_widget_host_view_mac.mm
===================================================================
--- chrome/browser/renderer_host/render_widget_host_view_mac.mm	(revision 30343)
+++ chrome/browser/renderer_host/render_widget_host_view_mac.mm	(working copy)
@@ -5,7 +5,7 @@
 #include "chrome/browser/renderer_host/render_widget_host_view_mac.h"
 
 #include "base/histogram.h"
-#include "base/scoped_nsobject.h"
+#import "base/scoped_nsobject.h"
 #include "base/string_util.h"
 #include "base/sys_string_conversions.h"
 #include "chrome/browser/browser_trial.h"
@@ -544,7 +544,7 @@
   if (ignoreKeyEvents_)
     return NO;
 
-  // We have some magic in |CrApplication sendEvent:| that always sends key 
+  // We have some magic in |CrApplication sendEvent:| that always sends key
   // events to |keyEvent:| so that cocoa doesn't have a chance to intercept it.
   DCHECK([[self window] firstResponder] != self);
   return NO;
@@ -554,8 +554,7 @@
   if (ignoreKeyEvents_)
     return;
 
-  // TODO(avi): Possibly kill self? See RenderWidgetHostViewWin::OnKeyEvent and
-  // http://b/issue?id=1192881 .
+  scoped_nsobject<RenderWidgetHostViewCocoa> keepSelfAlive([self retain]);

[pink (ping after 24hrs), 2009/10/28 19:56:40]

in mozilla these were generally named kungFuDeathGrip with nsCOMPtr :=)

 
   // Don't cancel child popups; the key events are probably what's triggering
   // the popup in the first place.
@@ -591,7 +590,14 @@
   // To send an onkeydown() event before an onkeypress() event, we should
   // dispatch this NSKeyDown event AFTER sending it to the renderer.
   // (See <https://bugs.webkit.org/show_bug.cgi?id=25119>).
-  if ([theEvent type] == NSKeyDown)
+  //
+  // If this object's retainCount is 1, the only reference is the one held by
+  // keepSelfAlive.  All other references may have been destroyed in the
+  // RenderWidgetHost::ForwardKeyboardEvent call above if it resulted in tab
+  // closure.  Were it not for that single reference, this object would
+  // already be deallocated.  In that case, there's no point in calling
+  // -interpretKeyEvents:.
+  if ([self retainCount] > 1 && [theEvent type] == NSKeyDown)
     [self interpretKeyEvents:[NSArray arrayWithObject:theEvent]];
 
   // Possibly autohide the cursor.
@@ -1255,4 +1261,3 @@
 }
 
 @end
-