Upstream Chrome on iOS source code [10/11].

ios/chrome/browser/web/early_page_script_perftest.mm

+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "base/mac/bundle_locations.h"
+#include "base/mac/scoped_nsobject.h"
+#include "base/timer/elapsed_timer.h"
+#include "ios/chrome/test/base/perf_test_ios.h"
+#import "ios/web/public/test/js_test_util.h"
+#include "ios/web/public/test/test_browser_state.h"
+#import "ios/web/public/web_view_creation_util.h"
+#import "ios/web/web_state/js/page_script_util.h"
+
+#import <Foundation/Foundation.h>
+#import <WebKit/WebKit.h>
+
+namespace {
+
+// Class for testing early page script injection into WKWebView.
+// TODO(crbug.com/583218): improve this test to use WKUserScript injections.
+class EarlyPageScriptPerfTest : public PerfTest {
+ protected:
+  EarlyPageScriptPerfTest() : PerfTest("Early Page Script for WKWebView") {
+    web_view_.reset([web::BuildWKWebView(CGRectZero, &browser_state_) retain]);
+  }
+
+  // Injects early script into WKWebView.
+  void InjectEarlyScript() {
+    web::ExecuteJavaScript(web_view_, web::GetEarlyPageScript());
+  }
+
+  // BrowserState required for web view creation.
+  web::TestBrowserState browser_state_;
+  // WKWebView to test scripts injections.
+  base::scoped_nsobject<WKWebView> web_view_;
+};
+
+// Tests script loading time.
+TEST_F(EarlyPageScriptPerfTest, ScriptLoading) {
+  RepeatTimedRuns("Loading",
+                  ^base::TimeDelta(int) {
+                    base::ElapsedTimer timer;
+                    web::GetEarlyPageScript();
+                    return timer.Elapsed();
+                  },
+                  nil);
+}
+
+// Tests injection time into a bare web view.
+TEST_F(EarlyPageScriptPerfTest, BareWebViewInjection) {
+  RepeatTimedRuns("Bare web view injection",
+                  ^base::TimeDelta(int) {
+                    base::ElapsedTimer timer;
+                    InjectEarlyScript();
+                    return timer.Elapsed();
+                  },
+                  nil);
+}
+
+}  // namespace