Modernize NavigationAndLoadCallbacksTest integration test.

Notable changes:

1.) Use C-functions helpers instead of WebIntTest method. This will
    allow to switch NavigationAndLoadCallbacksTest to a simpler base
    class in the future.
2.) Added test::WaitForPageToFinishLoading C-function, which can be
    used across multiple tests to wait for pageload.
3.) Removed extra usage of web:: because NavigationAndLoadCallbacksTest
    is already placed into web namespace.
4.) Removed web_state()->SetDelegate(nullptr); calls, because unlike
    WebIntTest, WebTestWithWebState does not set a web delegate.

Bug: None
Cq-Include-Trybots: master.tryserver.chromium.mac:ios-simulator-cronet;master.tryserver.chromium.mac:ios-simulator-full-configs
Change-Id: If5f26f1da40a90fde6378964b0f29a6ac30c16bb
Reviewed-on: https://chromium-review.googlesource.com/1056203
Commit-Queue: Kurt Horimoto <kkhorimoto@chromium.org>
Reviewed-by: Kurt Horimoto <kkhorimoto@chromium.org>
Cr-Commit-Position: refs/heads/master@{#558908}

ios/chrome/test/app/navigation_test_util.mm

@@ -5,15 +5,12 @@
 #include "ios/chrome/test/app/navigation_test_util.h"
 
 #import "ios/chrome/test/app/chrome_test_util.h"
-#import "ios/testing/wait_util.h"
 #import "ios/web/public/test/navigation_test_util.h"
 
 #if !defined(__has_feature) || !__has_feature(objc_arc)
 #error "This file requires ARC support."
 #endif
 
-using testing::WaitUntilConditionOrTimeout;
-
 namespace chrome_test_util {
 
 void LoadUrl(const GURL& url) {
@@ -25,9 +22,7 @@ bool IsLoading() {
 }
 
 bool WaitForPageToFinishLoading() {
-  return WaitUntilConditionOrTimeout(testing::kWaitForPageLoadTimeout, ^{
-    return !IsLoading();
-  });
+  return web::test::WaitForPageToFinishLoading(GetCurrentWebState());
 }
 
 }  // namespace chrome_test_util

ios/web/public/test/navigation_test_util.h

@@ -12,7 +12,11 @@ namespace web {
 namespace test {
 
 // Loads |url| in |web_state| with transition of type ui::PAGE_TRANSITION_TYPED.
-void LoadUrl(web::WebState* web_state, const GURL& url);
+void LoadUrl(WebState* web_state, const GURL& url);
+
+// Returns true if the current page in the current WebState finishes loading
+// within a timeout.
+bool WaitForPageToFinishLoading(WebState* web_state) WARN_UNUSED_RESULT;
 
 }  // namespace test
 }  // namespace web

ios/web/public/test/navigation_test_util.mm

@@ -4,13 +4,15 @@
 
 #import "ios/web/public/test/navigation_test_util.h"
 
+#import "ios/testing/wait_util.h"
 #import "ios/web/public/navigation_manager.h"
+#import "ios/web/public/web_state/web_state.h"
 
 #if !defined(__has_feature) || !__has_feature(objc_arc)
 #error "This file requires ARC support."
 #endif
 
-using web::NavigationManager;
+using testing::WaitUntilConditionOrTimeout;
 
 namespace web {
 namespace test {
@@ -22,5 +24,11 @@ void LoadUrl(web::WebState* web_state, const GURL& url) {
   navigation_manager->LoadURLWithParams(params);
 }
 
+bool WaitForPageToFinishLoading(WebState* web_state) {
+  return WaitUntilConditionOrTimeout(testing::kWaitForPageLoadTimeout, ^{
+    return !web_state->IsLoading();
+  });
+}
+
 }  // namespace test
 }  // namespace web