Update ExtensionInstallChecker to use PreloadCheck classes

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 b12bc17950de05927ec82b86c69a8736e5b65232..6ba3b1d30ac9fccba7c9f3ac669d25c1b73fc87f 100644
--- a/extensions/browser/preload_check_test_util.cc
+++ b/extensions/browser/preload_check_test_util.cc
@@ -9,10 +9,14 @@
 #include "base/logging.h"
 #include "base/memory/ptr_util.h"
 #include "base/run_loop.h"
+#include "base/single_thread_task_runner.h"
+#include "base/threading/thread_task_runner_handle.h"
+#include "extensions/common/extension.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace extensions {
 
+// PreloadCheckRunner:
 PreloadCheckRunner::PreloadCheckRunner() : called_(false) {}
 PreloadCheckRunner::~PreloadCheckRunner() {}
 
@@ -47,4 +51,33 @@ void PreloadCheckRunner::WaitForIdle() {
   run_loop_->RunUntilIdle();
 }
 
+// PreloadCheckStub:
+PreloadCheckStub::PreloadCheckStub(bool is_async)
+    : PreloadCheck(nullptr), is_async_(is_async) {}
+
+PreloadCheckStub::~PreloadCheckStub() {}
+
+void PreloadCheckStub::AddError(Error error) {
+  errors_.insert(error);
+}
+
+void PreloadCheckStub::Start(ResultCallback callback) {
+  DCHECK(!callback.is_null());
+  if (is_async_) {
+    base::ThreadTaskRunnerHandle::Get()->PostTask(
+        FROM_HERE, base::Bind(&PreloadCheckStub::StartInternal,
+                              base::Unretained(this), base::Passed(&callback)));
+  } else {
+    StartInternal(std::move(callback));
+  }
+}
+
+void PreloadCheckStub::StartInternal(ResultCallback callback) {
+  std::move(callback).Run(errors_);
+}
+
+base::string16 PreloadCheckStub::GetErrorMessage() const {
+  return message_;
+}
+
 }  // namespace extensions