Insert diagnostics in an attempt to track down a crash in popup menus...

chrome/browser/renderer_host/render_widget_host_view_mac.mm

 // Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/renderer_host/render_widget_host_view_mac.h"
 
 #include "base/histogram.h"
 #import "base/scoped_nsobject.h"
 #include "base/string_util.h"
 #include "base/sys_string_conversions.h"
@@ skipping 401 matching lines @@
                   initialIndex:selected_item];
   }
 
   int window_num = [[parent_view_ window] windowNumber];
   NSEvent* event =
       webkit_glue::EventWithMenuAction([menu_runner menuItemWasChosen],
                                        window_num, item_height,
                                        [menu_runner indexOfSelectedItem],
                                        position, view_rect);
 
+  // CHECK()s inserted to diagnose the crash in http://crbug.com/31716
+  // TODO(pamg): Remove when no longer needed.
+  CHECK(render_widget_host_);
   if ([menu_runner menuItemWasChosen]) {
     // Simulate a menu selection event.
+    CHECK(cocoa_view_);
     const WebMouseEvent& mouse_event =
         WebInputEventFactory::mouseEvent(event, cocoa_view_);
     render_widget_host_->ForwardMouseEvent(mouse_event);
   } else {
     // Simulate a menu dismiss event.
     NativeWebKeyboardEvent keyboard_event(event);
     render_widget_host_->ForwardKeyboardEvent(keyboard_event);
   }
 }
 
@@ skipping 136 matching lines @@
     editCommand_helper_.reset(new RWHVMEditCommandHelper);
     editCommand_helper_->AddEditingSelectorsToClass([self class]);
 
     renderWidgetHostView_.reset(r);
     canBeKeyView_ = YES;
     closeOnDeactivate_ = NO;
   }
   return self;
 }
 
+// Used only to diagnose the crash in http://crbug.com/31716
+// TODO(pamg): Remove when no longer needed.
+- (void)dealloc {
+  renderWidgetHostView_->clear_cocoa_view();
+  [super dealloc];
+}
+
 - (void)setCanBeKeyView:(BOOL)can {
   canBeKeyView_ = can;
 }
 
 - (void)setCloseOnDeactivate:(BOOL)b {
   closeOnDeactivate_ = b;
 }
 
 - (void)mouseEvent:(NSEvent*)theEvent {
   // Don't cancel child popups; killing them on a mouse click would prevent the
@@ skipping 796 matching lines @@
     event.skip_in_browser = true;
     renderWidgetHostView_->render_widget_host_->ForwardKeyboardEvent(event);
   } else {
     renderWidgetHostView_->render_widget_host_->ImeConfirmComposition(
         UTF8ToUTF16([im_text UTF8String]));
   }
   renderWidgetHostView_->im_composing_ = false;
 }
 
 @end