Introduce ui_test_utils::FocusView and de-flake OmniboxViewTest.BeginningShownAfterBlur

chrome/test/base/interactive_test_utils_mac.mm

Index: chrome/test/base/interactive_test_utils_mac.mm
diff --git a/chrome/test/base/interactive_test_utils_mac.mm b/chrome/test/base/interactive_test_utils_mac.mm
index e2d5cdb5fa17b0210ee3a2fe54d8cd36e0522d80..fcf5f124f1f1e719067dafe11595c758642694f5 100644
--- a/chrome/test/base/interactive_test_utils_mac.mm
+++ b/chrome/test/base/interactive_test_utils_mac.mm
@@ -78,6 +78,14 @@ void ClickOnView(const Browser* browser, ViewID vid) {
   content::RunMessageLoop();
 }
 
+void FocusView(const Browser* browser, ViewID vid) {
+   NSWindow* window = browser->window()->GetNativeWindow();
+   DCHECK(window);
+   NSView* view = view_id_util::GetView(window, vid);
+   DCHECK(view);
+   [window makeFirstResponder:view];
+ }
+
 void HideNativeWindow(gfx::NativeWindow window) {
   [window orderOut:nil];
 }