[ObjC ARC] Converts ios/chrome/browser/metrics:eg_tests to ARC.

ios/chrome/browser/metrics/tab_usage_recorder_egtest.mm

 // Copyright 2016 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.
 
 #import <EarlGrey/EarlGrey.h>
 #import <XCTest/XCTest.h>
 
 #include "base/mac/bind_objc_block.h"
 #include "base/memory/ptr_util.h"
 #include "base/strings/stringprintf.h"
@@ skipping 22 matching lines @@
 #import "ios/chrome/test/earl_grey/chrome_test_case.h"
 #import "ios/testing/wait_util.h"
 #import "ios/web/public/test/earl_grey/web_view_matchers.h"
 #import "ios/web/public/test/http_server.h"
 #import "ios/web/public/test/http_server_util.h"
 #include "ios/web/public/test/response_providers/delayed_response_provider.h"
 #include "ios/web/public/test/response_providers/html_response_provider.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/base/l10n/l10n_util_mac.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 namespace {
 
 const char kTestUrl1[] =
     "http://ios/testing/data/http_server_files/memory_usage.html";
 const char kURL1FirstWord[] = "Page";
 const char kTestUrl2[] =
     "http://ios/testing/data/http_server_files/fullscreen.html";
 const char kURL2FirstWord[] = "Rugby";
 const char kClearPageScript[] = "document.body.innerHTML='';";
 
@@ skipping 272 matching lines @@
   // Switch between the tabs. They are currently in memory.
   chrome_test_util::SelectTabAtIndexInCurrentMode(0);
 
   // Verify that no page-load count has been recorded.
   histogramTester.ExpectTotalCount(kPageLoadsBeforeEvictedTabSelected, 0,
                                    failureBlock);
 
   // Reload each tab.
   for (NSUInteger i = 0; i < numberOfTabs; i++) {
     chrome_test_util::SelectTabAtIndexInCurrentMode(i);
-    // Clear the page so that we can check when pade reload is complete.
+    // Clear the page so that we can check when page reload is complete.
     __block bool finished = false;
     chrome_test_util::GetCurrentWebState()->ExecuteJavaScript(
         base::UTF8ToUTF16(kClearPageScript),
-        base::BindBlock(^(const base::Value*) {
+        base::BindBlockArc(^(const base::Value*) {
           finished = true;
         }));
 
     GREYAssert(testing::WaitUntilConditionOrTimeout(1.0,
                                                     ^{
                                                       return finished;
                                                     }),
                @"JavaScript to reload each tab did not finish");
     [ChromeEarlGreyUI reload];
     [[EarlGrey selectElementWithMatcher:chrome_test_util::WebViewContainingText(
@@ skipping 598 matching lines @@
     [[GREYUIThreadExecutor sharedInstance] drainUntilIdle];
   }
   // The deleted tabs are purged during foregrounding and backgrounding.
   chrome_test_util::SimulateTabsBackgrounding();
   // Make sure |evicted_tabs_| purged the deleted tabs.
   int evicted = chrome_test_util::GetEvictedMainTabCount();
   GREYAssertEqual(evicted, 0, @"Check number of evicted tabs");
 }
 
 @end