--- a/toolkit/components/url-classifier/nsUrlClassifierPrefixSet.cpp
+++ b/toolkit/components/url-classifier/nsUrlClassifierPrefixSet.cpp
@@ -1,17 +1,16 @@
 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 #include "nsUrlClassifierPrefixSet.h"
 #include "nsIUrlClassifierPrefixSet.h"
-#include "crc32c.h"
 #include "nsCOMPtr.h"
 #include "nsDebug.h"
 #include "nsPrintfCString.h"
 #include "nsTArray.h"
 #include "nsString.h"
 #include "nsTArray.h"
 #include "nsThreadUtils.h"
 #include "nsNetUtil.h"
@@ -30,32 +29,19 @@ static LazyLogModule gUrlClassifierPrefi
 #define LOG(args) \
   MOZ_LOG(gUrlClassifierPrefixSetLog, mozilla::LogLevel::Debug, args)
 #define LOG_ENABLED() \
   MOZ_LOG_TEST(gUrlClassifierPrefixSetLog, mozilla::LogLevel::Debug)
 
 NS_IMPL_ISUPPORTS(nsUrlClassifierPrefixSet, nsIUrlClassifierPrefixSet,
                   nsIMemoryReporter)
 
-template <typename T>
-static void CalculateTArrayChecksum(const nsTArray<T>& aArray,
-                                    uint32_t* outChecksum) {
-  *outChecksum = ~0;
-
-  for (size_t i = 0; i < aArray.Length(); i++) {
-    const T& element = aArray[i];
-    const void* pointer = &element;
-    *outChecksum = ComputeCrc32c(
-        *outChecksum, reinterpret_cast<const uint8_t*>(pointer), sizeof(void*));
-  }
-}
 
 nsUrlClassifierPrefixSet::nsUrlClassifierPrefixSet()
     : mLock("nsUrlClassifierPrefixSet.mLock"),
-      mIndexDeltasChecksum(~0),
       mTotalPrefixes(0) {}
 
 NS_IMETHODIMP
 nsUrlClassifierPrefixSet::Init(const nsACString& aName) {
   mName = aName;
   mMemoryReportPath = nsPrintfCString(
       "explicit/storage/prefix-set/%s",
       (!aName.IsEmpty() ? PromiseFlatCString(aName).get() : "?!"));
@@ -67,17 +53,16 @@ nsUrlClassifierPrefixSet::Init(const nsA
 
 nsUrlClassifierPrefixSet::~nsUrlClassifierPrefixSet() {
   UnregisterWeakMemoryReporter(this);
 }
 
 void nsUrlClassifierPrefixSet::Clear() {
   LOG(("[%s] Clearing PrefixSet", mName.get()));
   mIndexDeltas.Clear();
-  mIndexDeltasChecksum = ~0;
   mIndexPrefixes.Clear();
   mTotalPrefixes = 0;
 }
 
 NS_IMETHODIMP
 nsUrlClassifierPrefixSet::SetPrefixes(const uint32_t* aArray,
                                       uint32_t aLength) {
   MutexAutoLock lock(mLock);
@@ -141,25 +126,21 @@ nsresult nsUrlClassifierPrefixSet::MakeP
     }
     previousItem = aPrefixes[i];
   }
 
   mTotalPrefixes = aLength;
 
   mIndexDeltas.LastElement().Compact();
 
-  // The hdr pointer of the last element of nsTArray may change after calling
-  // mIndexDeltas.LastElement().Compact(), so calculate checksum after the call.
-  CalculateTArrayChecksum(mIndexDeltas, &mIndexDeltasChecksum);
-
   mIndexDeltas.Compact();
   mIndexPrefixes.Compact();
   MOZ_ASSERT(mIndexPrefixes.Length() == mIndexDeltas.Length());
 
-  LOG(("Total number of indices: %d (crc=%u)", aLength, mIndexDeltasChecksum));
+  LOG(("Total number of indices: %d", aLength));
   LOG(("Total number of deltas: %d", totalDeltas));
   LOG(("Total number of delta chunks: %zu", mIndexDeltas.Length()));
 
   return NS_OK;
 }
 
 nsresult nsUrlClassifierPrefixSet::GetPrefixesNative(
     FallibleTArray<uint32_t>& outArray) {
@@ -438,29 +419,16 @@ uint32_t nsUrlClassifierPrefixSet::Calcu
 }
 
 nsresult nsUrlClassifierPrefixSet::WritePrefixes(
     nsCOMPtr<nsIOutputStream>& out) const {
   MutexAutoLock lock(mLock);
 
   mCanary.Check();
 
-  // In Bug 1362761, crashes happened while reading mIndexDeltas[i].
-  // We suspect that this is due to memory corruption so to test this
-  // hypothesis, we will crash the browser. Once we have established
-  // memory corruption as the root cause, we can attempt to gracefully
-  // handle this.
-  uint32_t checksum;
-  CalculateTArrayChecksum(mIndexDeltas, &checksum);
-  if (checksum != mIndexDeltasChecksum) {
-    LOG(("[%s] The contents of mIndexDeltas doesn't match the checksum!",
-         mName.get()));
-    MOZ_CRASH("Memory corruption detected in mIndexDeltas.");
-  }
-
   uint32_t written;
   uint32_t writelen = sizeof(uint32_t);
   const uint32_t magic = PREFIXSET_VERSION_MAGIC;
   nsresult rv =
       out->Write(reinterpret_cast<const char*>(&magic), writelen, &written);
   NS_ENSURE_SUCCESS(rv, rv);
   NS_ENSURE_TRUE(written == writelen, NS_ERROR_FAILURE);
 

--- a/toolkit/components/url-classifier/nsUrlClassifierPrefixSet.h
+++ b/toolkit/components/url-classifier/nsUrlClassifierPrefixSet.h
@@ -72,17 +72,16 @@ class nsUrlClassifierPrefixSet final : p
   // list of fully stored prefixes, that also form the
   // start of a run of deltas in mIndexDeltas.
   nsTArray<uint32_t> mIndexPrefixes;
   // array containing arrays of deltas from indices.
   // Index to the place that matches the closest lower
   // prefix from mIndexPrefix. Then every "delta" corresponds
   // to a prefix in the PrefixSet.
   nsTArray<nsTArray<uint16_t> > mIndexDeltas;
-  uint32_t mIndexDeltasChecksum;
 
   // how many prefixes we have.
   uint32_t mTotalPrefixes;
 
   nsCString mName;
   nsCString mMemoryReportPath;
   mozilla::CorruptionCanary mCanary;
 };