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

content/shell/shell_browser_main.cc

 // Copyright (c) 2011 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 "content/shell/shell_browser_main.h"
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/message_loop.h"
 #include "base/threading/thread.h"
 #include "base/threading/thread_restrictions.h"
 #include "content/browser/browser_process_sub_thread.h"
 #include "content/browser/download/download_file_manager.h"
 #include "content/browser/download/save_file_manager.h"
 #include "content/browser/plugin_service_impl.h"
+#include "content/public/common/main_function_params.h"
 #include "content/shell/shell.h"
 #include "content/shell/shell_browser_context.h"
 #include "content/shell/shell_content_browser_client.h"
+#include "content/shell/shell_switches.h"
 #include "net/base/net_module.h"
 #include "ui/base/clipboard/clipboard.h"
 
 namespace content {
 
 static GURL GetStartupURL() {
   const CommandLine::StringVector& args =
       CommandLine::ForCurrentProcess()->GetArgs();
   if (args.empty())
     return GURL("http://www.google.com/");
 
   return GURL(args[0]);
 }
 
 ShellBrowserMainParts::ShellBrowserMainParts(
     const content::MainFunctionParams& parameters)
-    : BrowserMainParts() {
+    : BrowserMainParts(),
+      dump_as_text_(parameters.command_line.HasSwitch(switches::kTree)) {
   ShellContentBrowserClient* shell_browser_client =
       static_cast<ShellContentBrowserClient*>(
           content::GetContentClient()->browser());
   shell_browser_client->set_shell_browser_main_parts(this);
 }
 
 ShellBrowserMainParts::~ShellBrowserMainParts() {
 }
 
 void ShellBrowserMainParts::PreMainMessageLoopRun() {
   browser_context_.reset(new ShellBrowserContext(this));
 
   Shell::PlatformInitialize();
   net::NetModule::SetResourceProvider(Shell::PlatformResourceProvider);
 
-  Shell::CreateNewWindow(browser_context_.get(),
-                         GetStartupURL(),
-                         NULL,
-                         MSG_ROUTING_NONE,
-                         NULL);
+  Shell* shell = Shell::CreateNewWindow(browser_context_.get(),
+                                        GetStartupURL(),
+                                        NULL,
+                                        MSG_ROUTING_NONE,
+                                        NULL);
+  shell->SetDumpAsText(dump_as_text_);
 }
 
 void ShellBrowserMainParts::PostMainMessageLoopRun() {
   browser_context_.reset();
 }
 
 bool ShellBrowserMainParts::MainMessageLoopRun(int* result_code) {
   return false;
 }
 
 ui::Clipboard* ShellBrowserMainParts::GetClipboard() {
   if (!clipboard_.get())
     clipboard_.reset(new ui::Clipboard());
   return clipboard_.get();
 }
 
 }  // namespace