components: Cleanup class/struct fwd declarations

components/test_runner/web_widget_test_client.h

Index: components/test_runner/web_widget_test_client.h
diff --git a/components/test_runner/web_widget_test_client.h b/components/test_runner/web_widget_test_client.h
index fc8586f4d1b5e911cd254a29f202a7df76d5a831..9275f39945da7b993692b20ed8c5f2b17d5ff308 100644
--- a/components/test_runner/web_widget_test_client.h
+++ b/components/test_runner/web_widget_test_client.h
@@ -9,16 +9,11 @@
 #include "base/memory/weak_ptr.h"
 #include "third_party/WebKit/public/web/WebWidgetClient.h"
 
-namespace blink {
-class WebWidget;
-}  // namespace blink
-
 namespace test_runner {
 
 class TestRunner;
 class TestRunnerForSpecificView;
 class WebTestDelegate;
-class WebViewTestProxyBase;
 class WebWidgetTestProxyBase;
 
 // WebWidgetTestClient implements WebWidgetClient interface, providing behavior