Update NetErrorDiagnosticDialog for ephemeral Guest profiles.

Net Error diagnostic dialog is updated to be NOT shown for ephemeral
Guest profiles.

This change is behind disabled |EnableEphemeralGuestProfilesOnDesktop|
flag.
Please see go/ephemeral-guest-profiles for more context.

Bug: 1125474
Change-Id: I468af46df1095e642d76945929327c0aa9106e6b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2470521Reviewed-by: Asanka Herath <asanka@chromium.org>
Commit-Queue: Ramin Halavati <rhalavati@chromium.org>
Cr-Commit-Position: refs/heads/master@{#817362}

chrome/browser/net/net_error_diagnostics_dialog_win.cc

@@ -89,7 +89,8 @@ bool CanShowNetworkDiagnosticsDialog(content::WebContents* web_contents) {
       Profile::FromBrowserContext(web_contents->GetBrowserContext());
   // The Windows diagnostic tool logs URLs it's run with, so it shouldn't be
   // used with incognito or guest profiles.  See https://crbug.com/929141
-  return !profile->IsOffTheRecord() && !profile->IsGuestSession();
+  return !profile->IsIncognitoProfile() && !profile->IsGuestSession() &&
+         !profile->IsEphemeralGuestProfile();
 }
 
 void ShowNetworkDiagnosticsDialog(content::WebContents* web_contents,