[iOS] Add experimental new keyboard accessory view.

ios/chrome/browser/experimental_flags.h

Index: ios/chrome/browser/experimental_flags.h
diff --git a/ios/chrome/browser/experimental_flags.h b/ios/chrome/browser/experimental_flags.h
index f3a046b0641a031b34a3cf78da0875fc0f8b4256..03d0a9dcba1f92c161eb2686722685b49c7b8822 100644
--- a/ios/chrome/browser/experimental_flags.h
+++ b/ios/chrome/browser/experimental_flags.h
@@ -106,6 +106,9 @@ bool IsNativeAppLauncherEnabled();
 // Whether a new version of FeedbackKit is the preferred feedback UI provider.
 bool IsNewFeedbackKitEnabled();
 
+// Whether the keyboard accessory view with camera search is enabled.
+bool IsKeyboardAccessoryViewWithCameraSearchEnabled();
+
 }  // namespace experimental_flags
 
 #endif  // IOS_CHROME_BROWSER_EXPERIMENTAL_FLAGS_H_