Add option --dump-render-tree to content_shell to dump the render tree as text.

content/shell/shell_browser_main.h

Index: content/shell/shell_browser_main.h
diff --git a/content/shell/shell_browser_main.h b/content/shell/shell_browser_main.h
index 2451761d45d6012ffd30ee8605cc8500cb338613..386575873b2bc14de84aea00a0b66512a91a80b5 100644
--- a/content/shell/shell_browser_main.h
+++ b/content/shell/shell_browser_main.h
@@ -46,6 +46,8 @@ class ShellBrowserMainParts : public BrowserMainParts {
 
   scoped_ptr<ui::Clipboard> clipboard_;
 
+  bool dump_as_text_;

[jam, 2012/01/26 18:47:34]

do we really need a member variable for this, instead of having whoever cares
check the command line?

[jochen (gone - plz use gerrit), 2012/01/27 08:49:56]

Done.

+
   DISALLOW_COPY_AND_ASSIGN(ShellBrowserMainParts);
 };