Implement GetBrowsingDataRemoverDelegate() for BrowserContext subclasses

content/public/test/test_browser_context.cc

Index: content/public/test/test_browser_context.cc
diff --git a/content/public/test/test_browser_context.cc b/content/public/test/test_browser_context.cc
index 3901e7d4203e376cec85d186bd6664cf7a5dae47..a69710d93a4bcbd954ae41b59c29cdaf990f5db9 100644
--- a/content/public/test/test_browser_context.cc
+++ b/content/public/test/test_browser_context.cc
@@ -127,6 +127,13 @@ BackgroundSyncController* TestBrowserContext::GetBackgroundSyncController() {
   return background_sync_controller_.get();
 }
 
+BrowsingDataRemoverDelegate*
+TestBrowserContext::GetBrowsingDataRemoverDelegate() {
+  // Most BrowsingDataRemover tests do not require a delegate
+  // (not even a mock one).
+  return nullptr;
+}
+
 net::URLRequestContextGetter* TestBrowserContext::CreateRequestContext(
       content::ProtocolHandlerMap* protocol_handlers,
       content::URLRequestInterceptorScopedVector request_interceptors) {