[ios] Do not show Default Browser fullscreen promo after crash

This change ensures that the default browser fullscreen promo does not
present in front of a Crash Restore Infobar, since it is the only
opportunity for the user to restore the tabs before the crash.

Fixed: 1163089
Change-Id: Ib819a05d8f9f0187716c89c48e04f05f435b2041
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2612104Reviewed-by: Rohit Rao <rohitrao@chromium.org>
Commit-Queue: Chris Lu <thegreenfrog@chromium.org>
Cr-Commit-Position: refs/heads/master@{#840441}

ios/chrome/browser/ui/main/scene_controller.mm

@@ -780,9 +780,10 @@ const char kMultiWindowOpenInNewWindowHistogram[] =
     self.sceneState.appState.startupInformation.restoreHelper = nil;
   }
 
-  // If skipping first run and not in Safe Mode, consider showing the default
-  // browser promo.
-  if (!firstRun && !self.sceneState.appState.isInSafeMode) {
+  // If skipping first run, not in Safe Mode, and the launch is not after a
+  // crash, consider showing the default browser promo.
+  if (!firstRun && !self.sceneState.appState.isInSafeMode &&
+      !self.sceneState.appState.postCrashLaunch) {
     // Show the Default Browser promo UI if the user's past behavior fits
     // the categorization of potentially interested users or if the user is
     // signed in. Do not show if it is determined that Chrome is already the