Remove ContentOffset helper from fullscreen tests.

There is an EarlGrey method that does the same thing.

Bug: 638674
Cq-Include-Trybots: master.tryserver.chromium.mac:ios-simulator-cronet;master.tryserver.chromium.mac:ios-simulator-full-configs
Change-Id: Ic4c0d8af6397477a1653367aeddf8b8ff060f70f
Reviewed-on: https://chromium-review.googlesource.com/777385
Commit-Queue: Mike Baxley <baxley@chromium.org>
Commit-Queue: Kurt Horimoto <kkhorimoto@chromium.org>
Reviewed-by: Kurt Horimoto <kkhorimoto@chromium.org>
Cr-Commit-Position: refs/heads/master@{#517518}

ios/chrome/browser/ui/fullscreen/fullscreen_egtest.mm

@@ -36,24 +36,6 @@ namespace {
 // The page height of test pages. This must be big enough to triger fullscreen.
 const int kPageHeightEM = 200;
 
-// TODO(crbug.com/638674): Move this to a shared location as it is a duplicate
-// of ios/web/shell/test/page_state_egtest.mm.
-// Returns a matcher for asserting that element's content offset matches the
-// given |offset|.
-id<GREYMatcher> ContentOffset(CGPoint offset) {
-  MatchesBlock matches = ^BOOL(UIScrollView* element) {
-    return CGPointEqualToPoint([element contentOffset], offset);
-  };
-  DescribeToBlock describe = ^(id<GREYDescription> description) {
-    [description appendText:@"contentOffset"];
-  };
-  return grey_allOf(
-      grey_kindOfClass([UIScrollView class]),
-      [[GREYElementMatcherBlock alloc] initWithMatchesBlock:matches
-                                           descriptionBlock:describe],
-      nil);
-}
-
 // Hides the toolbar by scrolling down.
 void HideToolbarUsingUI() {
   [[EarlGrey
@@ -107,7 +89,7 @@ void AssertURLIs(const GURL& expectedURL) {
   [[EarlGrey
       selectElementWithMatcher:web::WebViewScrollView(
                                    chrome_test_util::GetCurrentWebState())]
-      assertWithMatcher:ContentOffset(CGPointMake(0, yOffset))];
+      assertWithMatcher:grey_scrollViewContentOffset(CGPointMake(0, yOffset))];
 }
 
 // Verifies that the toolbar properly appears/disappears when scrolling up/down