[content shell] change how the main render view is picked for layout tests

content/shell/webkit_test_runner.cc

Index: content/shell/webkit_test_runner.cc
diff --git a/content/shell/webkit_test_runner.cc b/content/shell/webkit_test_runner.cc
index d21bdab0aeb59216336b8dc93cc3011ad1e701e9..122282af219d6f9bfba1cdfe00c1c631128a88bd 100644
--- a/content/shell/webkit_test_runner.cc
+++ b/content/shell/webkit_test_runner.cc
@@ -144,13 +144,10 @@ void CopyCanvasToBitmap(SkCanvas* canvas,  SkBitmap* snapshot) {
 
 WebKitTestRunner::WebKitTestRunner(RenderView* render_view)
     : RenderViewObserver(render_view),
-      RenderViewObserverTracker<WebKitTestRunner>(render_view),
-      is_main_window_(false) {
+      RenderViewObserverTracker<WebKitTestRunner>(render_view) {
 }
 
 WebKitTestRunner::~WebKitTestRunner() {
-  if (is_main_window_)
-    ShellRenderProcessObserver::GetInstance()->SetMainWindow(NULL, this);
 }
 
 // WebTestDelegate  -----------------------------------------------------------
@@ -259,7 +256,6 @@ bool WebKitTestRunner::OnMessageReceived(const IPC::Message& message) {
     IPC_MESSAGE_HANDLER(ShellViewMsg_CaptureImageDump, OnCaptureImageDump)
     IPC_MESSAGE_HANDLER(ShellViewMsg_SetCurrentWorkingDirectory,
                         OnSetCurrentWorkingDirectory)
-    IPC_MESSAGE_HANDLER(ShellViewMsg_SetIsMainWindow, OnSetIsMainWindow)
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
 
@@ -337,11 +333,6 @@ void WebKitTestRunner::OnSetCurrentWorkingDirectory(
   current_working_directory_ = current_working_directory;
 }
 
-void WebKitTestRunner::OnSetIsMainWindow() {
-  is_main_window_ = true;
-  ShellRenderProcessObserver::GetInstance()->SetMainWindow(render_view(), this);
-}
-
 SkCanvas* WebKitTestRunner::GetCanvas() {
   WebView* view = render_view()->GetWebView();
   const WebSize& size = view->size();