Move DumpBackForwardLists out of WebTestProxyBase.

components/test_runner/web_test_interfaces.h

Index: components/test_runner/web_test_interfaces.h
diff --git a/components/test_runner/web_test_interfaces.h b/components/test_runner/web_test_interfaces.h
index 0c12ef64540b8f69c5ad5381906fc9be5f205689..29942c1879c80d9d3a0bfbe49414daf34aa483f4 100644
--- a/components/test_runner/web_test_interfaces.h
+++ b/components/test_runner/web_test_interfaces.h
@@ -5,6 +5,8 @@
 #ifndef COMPONENTS_TEST_RUNNER_WEB_TEST_INTERFACES_H_
 #define COMPONENTS_TEST_RUNNER_WEB_TEST_INTERFACES_H_
 
+#include <vector>
+
 #include "base/macros.h"
 #include "base/memory/scoped_ptr.h"
 #include "components/test_runner/test_runner_export.h"
@@ -79,6 +81,9 @@ class TEST_RUNNER_EXPORT WebTestInterfaces {
   scoped_ptr<WebViewTestClient> CreateWebViewTestClient(
       WebTestProxyBase* web_test_proxy_base);
 
+  // Gets a list of currently opened windows created by the current test.
+  std::vector<blink::WebView*> GetWindowList();
+
  private:
   scoped_ptr<TestInterfaces> interfaces_;