isShowingErrorPage should have really useful info

chrome/android/java/src/org/chromium/chrome/browser/tab/Tab.java

Index: chrome/android/java/src/org/chromium/chrome/browser/tab/Tab.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/tab/Tab.java b/chrome/android/java/src/org/chromium/chrome/browser/tab/Tab.java
index d47e06c8c9edabe79cb02de6a744f18a7babc4e3..553beb1c033274c577defb738072bcc0e3947eba 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/tab/Tab.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/tab/Tab.java
@@ -1525,6 +1525,8 @@ public class Tab implements ViewGroup.OnHierarchyChangeListener,
      * @param showingErrorPage Whether an error page is being shown.
      */
     protected void didStartPageLoad(String validatedUrl, boolean showingErrorPage) {
+        setIsShowingErrorPage(showingErrorPage);

[Bernhard Bauer, 2017/02/13 22:51:30]

I think you could just update |mIsShowingErrorPage| directly.

[marcin, 2017/02/15 23:40:41]

I wanted to use method

[Bernhard Bauer, 2017/02/16 12:29:00]

Yes, but why? I don't see any advantage in going through the public interface,
in particular as the method has no additional logic beyond setting the member.

+
         updateTitle();
         removeSadTabIfPresent();
 
@@ -1561,6 +1563,7 @@ public class Tab implements ViewGroup.OnHierarchyChangeListener,
      * @param errorCode The error code causing the page to fail loading.
      */
     protected void didFailPageLoad(int errorCode) {
+        setIsShowingErrorPage(false);

[shaktisahu, 2017/02/16 18:54:53]

Why is this false? It should reflect the same value as |isErrorPage| as received
from NavigationHandle in TabWebContentsObserver. I believe |isErrorPage| is the
absolute truth about the state of the navigation.

         mIsBeingRestored = false;
         if (mTabUma != null) mTabUma.onLoadFailed(errorCode);
         for (TabObserver observer : mObservers) observer.onPageLoadFailed(this, errorCode);