Fix trigger for key functions IPH tooltip in touchless

This changes the trigger for key functions IPH from onPageLoadFinished
to onPageLoadStarted.

Related discussion: https://docs.google.com/a/google.com/presentation/d/1c-aVSZ_zsBuzCwQ4CrBJppmRQjiupa6PXmlC2OS-F-Q/edit?disco=AAAACv_xdz8

Bug: 924748
Change-Id: Ie0e0e20a9b2a92b32db3cd2ea240133dcac4f2cb
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1539867Reviewed-by: Michael Thiessen <mthiesse@chromium.org>
Commit-Queue: Mehran Mahmoudi <mahmoudi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#644459}

chrome/android/touchless/java/src/org/chromium/chrome/browser/touchless/ui/iph/KeyFunctionsIPHMediator.java

@@ -6,6 +6,7 @@ package org.chromium.chrome.browser.touchless.ui.iph;
 
 import org.chromium.base.task.PostTask;
 import org.chromium.chrome.browser.ActivityTabProvider;
+import org.chromium.chrome.browser.native_page.NativePageFactory;
 import org.chromium.chrome.browser.tab.Tab;
 import org.chromium.content_public.browser.UiThreadTaskTraits;
 import org.chromium.ui.base.CursorObserver;
@@ -75,10 +76,8 @@ public class KeyFunctionsIPHMediator implements CursorObserver {
         }
 
         @Override
-        public void onPageLoadFinished(Tab tab, String url) {
-            if (tab.isNativePage()) return;
-
-            if (tab.isShowingErrorPage()) return;
+        public void onPageLoadStarted(Tab tab, String url) {
+            if (NativePageFactory.isNativePageUrl(url, tab.isIncognito())) return;
 
             show(false);
         }