Remove usage of prototype patched method in DevTools layout test

Follow-up to https://crrev.com/c/2450031,
unlocks https://crrev.com/c/2450032

Bug: chromium:1135143
Change-Id: I792677962aa6de9ffcf20e7f4e6fe9300fbe0b57
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2450149Reviewed-by: Peter Marshall <petermarshall@chromium.org>
Commit-Queue: Sigurd Schneider <sigurds@chromium.org>
Cr-Commit-Position: refs/heads/master@{#814123}

third_party/blink/web_tests/http/tests/devtools/console/console-viewport-stick-to-bottom-onload.js

@@ -21,6 +21,6 @@
   await ConsoleTestRunner.waitForPendingViewportUpdates();
 
   TestRunner.addResult(
-      'Is at bottom: ' + viewport.element.isScrolledToBottom() + ', should stick: ' + viewport.stickToBottom());
+    'Is at bottom: ' + TestRunner.isScrolledToBottom(viewport.element) + ', should stick: ' + viewport.stickToBottom());
   TestRunner.completeTest();
 })();

third_party/blink/web_tests/http/tests/devtools/console/console-viewport-stick-to-bottom.js

@@ -144,7 +144,7 @@
   function dumpAndContinue(callback) {
     viewport.refresh();
     TestRunner.addResult(
-        'Is at bottom: ' + viewport.element.isScrolledToBottom() + ', should stick: ' + viewport.stickToBottom());
+      'Is at bottom: ' + TestRunner.isScrolledToBottom(viewport.element) + ', should stick: ' + viewport.stickToBottom());
     callback();
   }
 

third_party/blink/web_tests/http/tests/devtools/console/viewport-testing/console-key-expand.js

@@ -275,7 +275,7 @@
   function dumpScrollInfo() {
     viewport.refresh();
     let infoText =
-        'Is at bottom: ' + viewport.element.isScrolledToBottom() + ', should stick: ' + viewport.stickToBottom();
+      'Is at bottom: ' + TestRunner.isScrolledToBottom(viewport.element) + ', should stick: ' + viewport.stickToBottom();
     TestRunner.addResult(infoText);
   }
 

third_party/blink/web_tests/http/tests/devtools/console/viewport-testing/console-stick-to-bottom-expand-object.js

@@ -60,7 +60,7 @@
   function dumpInfo() {
     viewport.refresh();
     let infoText =
-        'Is at bottom: ' + viewport.element.isScrolledToBottom() + ', should stick: ' + viewport.stickToBottom();
+      'Is at bottom: ' + TestRunner.isScrolledToBottom(viewport.element) + ', should stick: ' + viewport.stickToBottom();
     const selectedElement = viewport.renderedElementAt(viewport._virtualSelectedIndex);
     if (selectedElement) {
       const selectedRect = selectedElement.getBoundingClientRect();

third_party/blink/web_tests/http/tests/devtools/console/viewport-testing/console-stick-to-bottom-with-large-prompt.js

@@ -68,7 +68,7 @@
   function dumpAndContinue(callback) {
     viewport.refresh();
     TestRunner.addResult(
-        'Is at bottom: ' + viewport.element.isScrolledToBottom() + ', should stick: ' + viewport.stickToBottom());
+      'Is at bottom: ' + TestRunner.isScrolledToBottom(viewport.element) + ', should stick: ' + viewport.stickToBottom());
     callback();
   }