Fix crash when user closes window prior to the "Confirm Install" prompt showing

chrome/browser/extensions/extension_install_prompt_show_params.h

Index: chrome/browser/extensions/extension_install_prompt_show_params.h
diff --git a/chrome/browser/extensions/extension_install_prompt_show_params.h b/chrome/browser/extensions/extension_install_prompt_show_params.h
new file mode 100644
index 0000000000000000000000000000000000000000..2fe6aa51c5b3b2ab6f56563155073a9518b563ba
--- /dev/null
+++ b/chrome/browser/extensions/extension_install_prompt_show_params.h
@@ -0,0 +1,64 @@
+// Copyright 2014 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.
+
+#ifndef CHROME_BROWSER_EXTENSIONS_EXTENSION_INSTALL_PROMPT_SHOW_PARAMS_H_
+#define CHROME_BROWSER_EXTENSIONS_EXTENSION_INSTALL_PROMPT_SHOW_PARAMS_H_
+
+#include "base/memory/scoped_ptr.h"
+#include "ui/gfx/native_widget_types.h"
+
+class NativeWindowTracker;
+class Profile;
+
+namespace content {
+class WebContents;
+}
+
+// Parameters to show an install prompt dialog. The parameters control:
+// - The dialog's parent window
+// - The browser window to use to open a new tab if a user clicks a link in the
+//   dialog.
+class ExtensionInstallPromptShowParams {
+ public:
+  explicit ExtensionInstallPromptShowParams(content::WebContents* web_contents);
+
+  // The most recently active browser window (or a new browser window if there
+  // are no browser windows) is used if a new tab needs to be opened.
+  ExtensionInstallPromptShowParams(Profile* profile, gfx::NativeWindow window);
+
+  virtual ~ExtensionInstallPromptShowParams();
+
+  Profile* profile() {
+    return profile_;
+  }
+
+  // The parent web contents for the dialog. Returns NULL if the web contents
+  // have been destroyed.
+  content::WebContents* GetParentWebContents();
+
+  // The parent window for the dialog. Returns NULL if the window has been
+  // destroyed.
+  gfx::NativeWindow GetParentWindow();
+
+  // Returns true if either the parent web contents or the parent window were
+  // destroyed.
+  bool WasParentDestroyed();
+
+ private:
+  void WebContentsDestroyed();
+
+  Profile* profile_;
+  content::WebContents* parent_web_contents_;
+  bool parent_web_contents_destroyed_;
+  gfx::NativeWindow parent_window_;
+
+  class WebContentsDestructionObserver;
+  scoped_ptr<WebContentsDestructionObserver> web_contents_destruction_observer_;
+
+  scoped_ptr<NativeWindowTracker> native_window_tracker_;
+
+  DISALLOW_COPY_AND_ASSIGN(ExtensionInstallPromptShowParams);
+};
+
+#endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_INSTALL_PROMPT_SHOW_PARAMS_H_