Content shell: Javascript dialogs, first pass, just Mac for now.

content/shell/shell.h

Index: content/shell/shell.h
diff --git a/content/shell/shell.h b/content/shell/shell.h
index 93499114e162ee04a76f7aed5fb6dd8e147e4bc5..0beb6dd7e53243dc750ae8b8d0af16500ad1ab50 100644
--- a/content/shell/shell.h
+++ b/content/shell/shell.h
@@ -27,7 +27,9 @@ class GURL;
 class WebContents;
 
 namespace content {
+
 class BrowserContext;
+class ShellJavaScriptDialogCreator;
 class SiteInstance;
 
 // This represents one window of the Content Shell, i.e. all the UI including
@@ -115,6 +117,7 @@ class Shell : public WebContentsDelegate,
                                   const GURL& target_url,
                                   WebContents* new_contents) OVERRIDE;
   virtual void DidNavigateMainFramePostCommit(WebContents* tab) OVERRIDE;
+  virtual JavaScriptDialogCreator* GetJavaScriptDialogCreator() OVERRIDE;
 #if defined(OS_MACOSX)
   virtual void HandleKeyboardEvent(
       const NativeWebKeyboardEvent& event) OVERRIDE;
@@ -143,6 +146,8 @@ class Shell : public WebContentsDelegate,
                      GObject*, guint, GdkModifierType);
 #endif
 
+  scoped_ptr<ShellJavaScriptDialogCreator> dialog_creator_;
+
   scoped_ptr<WebContents> web_contents_;
 
   // layoutTestController related variables.