Explicitly initialize secondary renderers for layout tests.

content/shell/renderer/layout_test/layout_test_content_renderer_client.cc

 // Copyright (c) 2014 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/renderer/layout_test/layout_test_content_renderer_client.h"
 
 #include "base/callback.h"
 #include "base/command_line.h"
 #include "base/debug/debugger.h"
 #include "components/test_runner/mock_credential_manager_client.h"
@@ skipping 93 matching lines @@
   BlinkTestRunner* test_runner = BlinkTestRunner::Get(render_view);
   test_runner->Reset(false /* for_new_test */);
 
   LayoutTestRenderProcessObserver::GetInstance()
       ->test_interfaces()
       ->TestRunner()
       ->InitializeWebViewWithMocks(render_view->GetWebView());
 
   test_runner::WebTestDelegate* delegate =
       LayoutTestRenderProcessObserver::GetInstance()->test_delegate();
-  if (delegate == static_cast<test_runner::WebTestDelegate*>(test_runner))
-    LayoutTestRenderProcessObserver::GetInstance()->SetMainWindow(render_view);
+  if (delegate == static_cast<test_runner::WebTestDelegate*>(test_runner)) {
+    // TODO(lukasza): Should this instead by done by BlinkTestRunner,
+    // when it gets notified by the browser that it is the main window?

[Łukasz Anforowicz, 2016/04/15 20:15:29]

This "todo" should be a long-term goal, but doing it today would introduce
(accidental) test failures, because this changes PrintMessage's behavior by
routing it through a different TestRunner::delegate_ (possibly swapped-out
and/or possible not listened to on the browser side).  Changing PrintMessage to
go through process/control message is tricky as discussed some time ago over
email.

+
+    // Let test_runner layer know what is the main test window.
+    LayoutTestRenderProcessObserver::GetInstance()
+        ->test_interfaces()
+        ->SetWebView(render_view->GetWebView(), proxy);

[Łukasz Anforowicz, 2016/04/15 20:15:29]

This just inlines what used to be in
LayoutTestRenderProcessObserver::SetMainWindow

+  }
 }
 
 WebMediaStreamCenter*
 LayoutTestContentRendererClient::OverrideCreateWebMediaStreamCenter(
     WebMediaStreamCenterClient* client) {
 #if defined(ENABLE_WEBRTC)
   test_runner::WebTestInterfaces* interfaces =
       LayoutTestRenderProcessObserver::GetInstance()->test_interfaces();
   return interfaces->CreateMediaStreamCenter(client);
 #else
@@ skipping 53 matching lines @@
 LayoutTestContentRendererClient::CreateMediaStreamRendererFactory() {
 #if defined(ENABLE_WEBRTC)
   return std::unique_ptr<MediaStreamRendererFactory>(
       new TestMediaStreamRendererFactory());
 #else
   return nullptr;
 #endif
 }
 
 }  // namespace content