Replace ExtensionInstallChecker with generic PreloadCheckGroup

extensions/browser/preload_check_test_util.cc

Index: extensions/browser/preload_check_test_util.cc
diff --git a/extensions/browser/preload_check_test_util.cc b/extensions/browser/preload_check_test_util.cc
index f5becf43ae4a7173c854c744f33c495fd2992565..7ef49cab36e52b87f7ad067933a447e125514451 100644
--- a/extensions/browser/preload_check_test_util.cc
+++ b/extensions/browser/preload_check_test_util.cc
@@ -36,8 +36,7 @@ void PreloadCheckRunner::RunUntilComplete(PreloadCheck* check) {
   Run(check);
   ASSERT_FALSE(called_);
 
-  run_loop_ = base::MakeUnique<base::RunLoop>();
-  run_loop_->Run();
+  WaitForComplete();
   ASSERT_TRUE(called_);
 }
 
@@ -51,18 +50,20 @@ void PreloadCheckRunner::WaitForIdle() {
   run_loop_->RunUntilIdle();
 }
 
+void PreloadCheckRunner::WaitForComplete() {
+  run_loop_ = base::MakeUnique<base::RunLoop>();
+  run_loop_->Run();
+}
+
 // PreloadCheckStub:
-PreloadCheckStub::PreloadCheckStub()
-    : PreloadCheck(nullptr), is_async_(false), weak_ptr_factory_(this) {}
+PreloadCheckStub::PreloadCheckStub(const Errors& errors)
+    : PreloadCheck(nullptr), errors_(errors), weak_ptr_factory_(this) {}
 
 PreloadCheckStub::~PreloadCheckStub() {}
 
-void PreloadCheckStub::AddError(Error error) {
-  errors_.insert(error);
-}
-
 void PreloadCheckStub::Start(ResultCallback callback) {
   DCHECK(!callback.is_null());
+  started_ = true;
   if (is_async_) {
     // TODO(michaelpg): Bind the callback directly and remove RunCallback
     // once crbug.com/704027 is addressed.
@@ -79,8 +80,4 @@ void PreloadCheckStub::RunCallback(ResultCallback callback) {
   std::move(callback).Run(errors_);
 }
 
-base::string16 PreloadCheckStub::GetErrorMessage() const {
-  return message_;
-}
-
 }  // namespace extensions