--- a/toolkit/components/resistfingerprinting/nsRFPService.cpp
+++ b/toolkit/components/resistfingerprinting/nsRFPService.cpp
@@ -340,17 +340,17 @@ nsresult nsRFPService::RandomMidpoint(lo
 
   nsCString hashResult = cache->Get(extraClampedTime, aContextMixin);
 
   if (hashResult.Length() != HASH_DIGEST_SIZE_BYTES) {  // Cache Miss =(
     // If someone has pased in the testing-only parameter, replace our seed with
     // it
     if (aSecretSeed != nullptr) {
       StaticMutexAutoLock lock(sLock);
-      if (sSecretMidpointSeed) {
+      if (sSecretMidpointSeed != nullptr) {
         delete[] sSecretMidpointSeed;
       }
       sSecretMidpointSeed = new uint8_t[kSeedSize];
       memcpy(sSecretMidpointSeed, aSecretSeed, kSeedSize);
     }
 
     // If we don't have a seed, we need to get one.
     if (MOZ_UNLIKELY(!sSecretMidpointSeed)) {
@@ -726,26 +726,26 @@ nsresult nsRFPService::Init() {
   NS_ENSURE_SUCCESS(rv, rv);
 #endif
 
   Preferences::RegisterCallbacks(PREF_CHANGE_METHOD(nsRFPService::PrefChanged),
                                  gCallbackPrefs, this);
 
   // We backup the original TZ value here.
   const char* tzValue = PR_GetEnv("TZ");
-  if (tzValue) {
+  if (tzValue != nullptr) {
     mInitialTZValue = nsCString(tzValue);
   }
 
   // Call Update here to cache the values of the prefs and set the timezone.
   UpdateRFPPref();
 
   // Create the LRU Cache when we initialize, to avoid accidently trying to
   // create it (and call ClearOnShutdown) on a non-main-thread
-  if (!sCache) {
+  if (sCache == nullptr) {
     sCache = new LRUCache();
   }
 
   return rv;
 }
 
 // This function updates only timing-related fingerprinting items
 void nsRFPService::UpdateTimers() {
@@ -783,23 +783,23 @@ void nsRFPService::UpdateRFPPref() {
     // We will not touch the TZ value if 'privacy.resistFingerprinting' is false
     // during the time of initialization.
     if (!mInitialTZValue.IsEmpty()) {
       nsAutoCString tzValue = NS_LITERAL_CSTRING("TZ=") + mInitialTZValue;
       static char* tz = nullptr;
 
       // If the tz has been set before, we free it first since it will be
       // allocated a new value later.
-      if (tz) {
+      if (tz != nullptr) {
         free(tz);
       }
       // PR_SetEnv() needs the input string been leaked intentionally, so
       // we copy it here.
       tz = ToNewCString(tzValue);
-      if (tz) {
+      if (tz != nullptr) {
         PR_SetEnv(tz);
       }
     } else {
 #if defined(XP_WIN)
       // For Windows, we reset the TZ to an empty string. This will make Windows
       // to use its system timezone.
       PR_SetEnv("TZ=");
 #else
@@ -838,17 +838,17 @@ void nsRFPService::StartShutdown() {
   }
   Preferences::UnregisterCallbacks(
       PREF_CHANGE_METHOD(nsRFPService::PrefChanged), gCallbackPrefs, this);
 }
 
 /* static */
 void nsRFPService::MaybeCreateSpoofingKeyCodes(const KeyboardLangs aLang,
                                                const KeyboardRegions aRegion) {
-  if (!sSpoofingKeyboardCodes) {
+  if (sSpoofingKeyboardCodes == nullptr) {
     sSpoofingKeyboardCodes =
         new nsDataHashtable<KeyboardHashKey, const SpoofingKeyboardCode*>();
   }
 
   if (KeyboardLang::EN == aLang) {
     switch (aRegion) {
       case KeyboardRegion::US:
         MaybeCreateSpoofingKeyCodesForEnUS();
@@ -936,26 +936,26 @@ bool nsRFPService::GetSpoofedKeyCodeInfo
     const dom::Document* aDoc, const WidgetKeyboardEvent* aKeyboardEvent,
     SpoofingKeyboardCode& aOut) {
   MOZ_ASSERT(aKeyboardEvent);
 
   KeyboardLangs keyboardLang = RFP_DEFAULT_SPOOFING_KEYBOARD_LANG;
   KeyboardRegions keyboardRegion = RFP_DEFAULT_SPOOFING_KEYBOARD_REGION;
   // If the document is given, we use the content language which is get from the
   // document. Otherwise, we use the default one.
-  if (aDoc) {
+  if (aDoc != nullptr) {
     nsAutoString language;
     aDoc->GetContentLanguage(language);
 
     // If the content-langauge is not given, we try to get langauge from the
     // HTML lang attribute.
     if (language.IsEmpty()) {
       dom::Element* elm = aDoc->GetHtmlElement();
 
-      if (elm) {
+      if (elm != nullptr) {
         elm->GetLang(language);
       }
     }
 
     // If two or more languages are given, per HTML5 spec, we should consider
     // it as 'unknown'. So we use the default one.
     if (!language.IsEmpty() && !language.Contains(char16_t(','))) {
       language.StripWhitespace();
@@ -970,17 +970,17 @@ bool nsRFPService::GetSpoofedKeyCodeInfo
 
   if (keyIdx == KEY_NAME_INDEX_USE_STRING) {
     keyName = aKeyboardEvent->mKeyValue;
   }
 
   KeyboardHashKey key(keyboardLang, keyboardRegion, keyIdx, keyName);
   const SpoofingKeyboardCode* keyboardCode = sSpoofingKeyboardCodes->Get(key);
 
-  if (keyboardCode) {
+  if (keyboardCode != nullptr) {
     aOut = *keyboardCode;
     return true;
   }
 
   return false;
 }
 
 /* static */
@@ -992,21 +992,21 @@ bool nsRFPService::GetSpoofedModifierSta
   // For modifier or control keys, we don't need to hide its modifier states.
   if (aKeyboardEvent->mKeyNameIndex != KEY_NAME_INDEX_USE_STRING) {
     return false;
   }
 
   // We will spoof the modifer state for Alt, Shift, and AltGraph.
   // We don't spoof the Control key, because it is often used
   // for command key combinations in web apps.
-  if (aModifier & (MODIFIER_ALT | MODIFIER_SHIFT | MODIFIER_ALTGRAPH)) {
+  if ((aModifier & (MODIFIER_ALT | MODIFIER_SHIFT | MODIFIER_ALTGRAPH)) != 0) {
     SpoofingKeyboardCode keyCodeInfo;
 
     if (GetSpoofedKeyCodeInfo(aDoc, aKeyboardEvent, keyCodeInfo)) {
-      aOut = keyCodeInfo.mModifierStates & aModifier;
+      aOut = ((keyCodeInfo.mModifierStates & aModifier) != 0);
       return true;
     }
   }
 
   return false;
 }
 
 /* static */
@@ -1070,17 +1070,17 @@ void nsRFPService::PrefChanged(const cha
     }
 #endif
   }
 }
 
 NS_IMETHODIMP
 nsRFPService::Observe(nsISupports* aObject, const char* aTopic,
                       const char16_t* aMessage) {
-  if (!strcmp(NS_XPCOM_SHUTDOWN_OBSERVER_ID, aTopic)) {
+  if (strcmp(NS_XPCOM_SHUTDOWN_OBSERVER_ID, aTopic) == 0) {
     StartShutdown();
   }
 #if defined(XP_WIN)
   else if (!strcmp(PROFILE_INITIALIZED_TOPIC, aTopic)) {
     // If we're e10s, then we don't need to run this, since the child process
     // will simply inherit the environment variable from the parent process, in
     // which case it's unnecessary to call _tzset().
     if (XRE_IsParentProcess() && !XRE_IsE10sParentProcess()) {