cherry-pick-6b84dc72351b.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Brendon Tiszka <btiszka@gmail.com>
Date: Tue, 20 Apr 2021 15:45:03 +0000
Subject: M86-LTS: Ensure that BrowserContext is not used after it has been
 freed
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Previously, it was possible for the BrowserContext to be destroyed
before ReportAnchorElementMetricsOnClick attempted to access it.

The fix uses the fact that NavigationPredictor extends
WebContentsObserver and checks that web_contents is still alive
before dereferencing BrowserContext. WebContents will always
outlive BrowserContext.

R=​lukasza@chromium.org, ryansturm@chromium.org

(cherry picked from commit 7313a810ae0b1361cbe8453bc5496654dee24c76)

Bug: 1197904
Change-Id: Iee4f126e92670a84d57c7a4ec7d6f702fb975c7e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2821639
Reviewed-by: Ryan Sturm <ryansturm@chromium.org>
Reviewed-by: Łukasz Anforowicz <lukasza@chromium.org>
Commit-Queue: Łukasz Anforowicz <lukasza@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#872021}
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2838328
Owners-Override: Achuith Bhandarkar <achuith@chromium.org>
Auto-Submit: Achuith Bhandarkar <achuith@chromium.org>
Reviewed-by: Artem Sumaneev <asumaneev@google.com>
Commit-Queue: Achuith Bhandarkar <achuith@chromium.org>
Cr-Commit-Position: refs/branch-heads/4240@{#1613}
Cr-Branched-From: f297677702651916bbf65e59c0d4bbd4ce57d1ee-refs/heads/master@{#800218}

diff --git a/AUTHORS b/AUTHORS
index d51c01045102715691a2e28cd44701a58a11cfa0..ae48471f7360a946447c915621236155e1399f86 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -148,6 +148,7 @@ Bobby Powers <bobbypowers@gmail.com>
 Branden Archer <bma4@zips.uakron.edu>
 Brendan Kirby <brendan.kirby@imgtec.com>
 Brendan Long <self@brendanlong.com>
+Brendon Tiszka <btiszka@gmail.com>
 Brian Clifton <clifton@brave.com>
 Brian G. Merrell <bgmerrell@gmail.com>
 Brian Konzman, SJ <b.g.konzman@gmail.com>
diff --git a/chrome/browser/navigation_predictor/navigation_predictor.cc b/chrome/browser/navigation_predictor/navigation_predictor.cc
index c532ddf44166215ae8eaa3d8433c7ed6fefdef06..f3799eaff3f960b162fbe5fb93e043804a26d121 100644
--- a/chrome/browser/navigation_predictor/navigation_predictor.cc
+++ b/chrome/browser/navigation_predictor/navigation_predictor.cc
@@ -506,6 +506,9 @@ void NavigationPredictor::ReportAnchorElementMetricsOnClick(
   DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
   DCHECK(base::FeatureList::IsEnabled(blink::features::kNavigationPredictor));
 
+  if (!web_contents())
+    return;
+
   if (browser_context_->IsOffTheRecord())
     return;
 
@@ -652,6 +655,9 @@ void NavigationPredictor::ReportAnchorElementMetricsOnLoad(
   // Each document should only report metrics once when page is loaded.
   DCHECK(navigation_scores_map_.empty());
 
+  if (!web_contents())
+    return;
+
   if (browser_context_->IsOffTheRecord())
     return;
 
@@ -897,6 +903,9 @@ void NavigationPredictor::MaybeTakeActionOnLoad(
 }
 
 void NavigationPredictor::MaybePrefetch() {
+  if (!web_contents())
+    return;
+
   // If prefetches aren't allowed here, this URL has already
   // been prefetched, or the current tab is hidden,
   // we shouldn't prefetch again.