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

content/shell/shell.cc

Index: content/shell/shell.cc
diff --git a/content/shell/shell.cc b/content/shell/shell.cc
index fcf684ce5e5d825b054f0f8a805e6decb3c1fb10..8677ae47a7a0de4555d6b2e15da1914199f5f7ab 100644
--- a/content/shell/shell.cc
+++ b/content/shell/shell.cc
@@ -7,8 +7,10 @@
 #include "base/message_loop.h"
 #include "base/path_service.h"
 #include "base/string_util.h"
+#include "content/browser/renderer_host/render_view_host.h"
 #include "content/browser/tab_contents/navigation_controller_impl.h"
 #include "content/browser/tab_contents/tab_contents.h"
+#include "content/shell/shell_messages.h"
 #include "ui/gfx/size.h"
 
 // Content area size for newly created windows.
@@ -103,6 +105,10 @@ void Shell::UpdateNavigationControls() {
   PlatformEnableUIControl(STOP_BUTTON, tab_contents_->IsLoading());
 }
 
+void Shell::SetDumpAsText(bool dump_as_text) {
+  dump_as_text_ = dump_as_text;
+}
+
 gfx::NativeView Shell::GetContentView() {
   if (!tab_contents_.get())
     return NULL;
@@ -114,6 +120,14 @@ void Shell::LoadingStateChanged(WebContents* source) {
   PlatformSetIsLoading(source->IsLoading());
 }
 
+void Shell::DidFinishLoad(WebContents* source) {
+  if (!dump_as_text_)
+    return;
+  RenderViewHost* render_view_host = source->GetRenderViewHost();
+  render_view_host->Send(
+      new ShellViewMsg_CaptureTextDump(render_view_host->routing_id(), false));
+}
+
 void Shell::WebContentsCreated(WebContents* source_contents,
                                int64 source_frame_id,
                                const GURL& target_url,