Track focused view in TestRunner instead of in BlinkTestRunner.

components/test_runner/web_test_runner.h

Index: components/test_runner/web_test_runner.h
diff --git a/components/test_runner/web_test_runner.h b/components/test_runner/web_test_runner.h
index 28baf6280dfbeb85296450cb560e54336c39d2d2..41b54dfaece263b337b2552bc2dd0425e96b04a3 100644
--- a/components/test_runner/web_test_runner.h
+++ b/components/test_runner/web_test_runner.h
@@ -79,6 +79,10 @@ class WebTestRunner {
   // method covers blink::WebCredentialManagerClient and
   // blink::WebSpellCheckClient.
   virtual void InitializeWebViewWithMocks(blink::WebView* web_view) = 0;
+
+  // Sets focus on the given view.  Internally tracks currently focused view,
+  // to aid in defocusing previously focused views at the right time.
+  virtual void SetFocus(blink::WebView* web_view, bool focus) = 0;
 };
 
 }  // namespace test_runner