--- a/dom/base/nsDocument.cpp
+++ b/dom/base/nsDocument.cpp
@@ -2878,23 +2878,16 @@ nsIDocument::InitCSP(nsIChannel* aChanne
   MOZ_ASSERT(!mScriptGlobalObject,
              "CSP must be initialized before mScriptGlobalObject is set!");
   if (!CSPService::sCSPEnabled) {
     MOZ_LOG(gCspPRLog, LogLevel::Debug,
            ("CSP is disabled, skipping CSP init for document %p", this));
     return NS_OK;
   }
 
-  // In case this channel was instrument to discard the CSP, then
-  // there is nothing for us to do here.
-  nsCOMPtr<nsILoadInfo> loadInfo = aChannel->GetLoadInfo();
-  if (loadInfo && loadInfo->GetAllowDocumentToBeAgnosticToCSP()) {
-    return NS_OK;
-  }
-
   nsAutoCString tCspHeaderValue, tCspROHeaderValue;
 
   nsCOMPtr<nsIHttpChannel> httpChannel;
   nsresult rv = GetHttpChannelHelper(aChannel, getter_AddRefs(httpChannel));
   if (NS_WARN_IF(NS_FAILED(rv))) {
     return rv;
   }
 
@@ -2911,16 +2904,17 @@ nsIDocument::InitCSP(nsIChannel* aChanne
   NS_ConvertASCIItoUTF16 cspROHeaderValue(tCspROHeaderValue);
 
   // Check if this is a document from a WebExtension.
   nsCOMPtr<nsIPrincipal> principal = NodePrincipal();
   auto addonPolicy = BasePrincipal::Cast(principal)->AddonPolicy();
 
   // Check if this is a signed content to apply default CSP.
   bool applySignedContentCSP = false;
+  nsCOMPtr<nsILoadInfo> loadInfo = aChannel->GetLoadInfo();
   if (loadInfo && loadInfo->GetVerifySignedContent()) {
     applySignedContentCSP = true;
   }
 
   // If there's no CSP to apply, go ahead and return early
   if (!addonPolicy &&
       !applySignedContentCSP &&
       cspHeaderValue.IsEmpty() &&

--- a/ipc/glue/BackgroundUtils.cpp
+++ b/ipc/glue/BackgroundUtils.cpp
@@ -402,17 +402,16 @@ LoadInfoToLoadInfoArgs(nsILoadInfo *aLoa
       aLoadInfo->GetSecurityFlags(),
       aLoadInfo->InternalContentPolicyType(),
       static_cast<uint32_t>(aLoadInfo->GetTainting()),
       aLoadInfo->GetUpgradeInsecureRequests(),
       aLoadInfo->GetBrowserUpgradeInsecureRequests(),
       aLoadInfo->GetBrowserWouldUpgradeInsecureRequests(),
       aLoadInfo->GetVerifySignedContent(),
       aLoadInfo->GetEnforceSRI(),
-      aLoadInfo->GetAllowDocumentToBeAgnosticToCSP(),
       aLoadInfo->GetForceAllowDataURI(),
       aLoadInfo->GetAllowInsecureRedirectToDataURI(),
       aLoadInfo->GetSkipContentPolicyCheckForWebRequest(),
       aLoadInfo->GetForceInheritPrincipalDropped(),
       aLoadInfo->GetInnerWindowID(),
       aLoadInfo->GetOuterWindowID(),
       aLoadInfo->GetParentOuterWindowID(),
       aLoadInfo->GetTopOuterWindowID(),
@@ -551,17 +550,16 @@ LoadInfoArgsToLoadInfo(const OptionalLoa
                           loadInfoArgs.securityFlags(),
                           loadInfoArgs.contentPolicyType(),
                           static_cast<LoadTainting>(loadInfoArgs.tainting()),
                           loadInfoArgs.upgradeInsecureRequests(),
                           loadInfoArgs.browserUpgradeInsecureRequests(),
                           loadInfoArgs.browserWouldUpgradeInsecureRequests(),
                           loadInfoArgs.verifySignedContent(),
                           loadInfoArgs.enforceSRI(),
-                          loadInfoArgs.allowDocumentToBeAgnosticToCSP(),
                           loadInfoArgs.forceAllowDataURI(),
                           loadInfoArgs.allowInsecureRedirectToDataURI(),
                           loadInfoArgs.skipContentPolicyCheckForWebRequest(),
                           loadInfoArgs.forceInheritPrincipalDropped(),
                           loadInfoArgs.innerWindowID(),
                           loadInfoArgs.outerWindowID(),
                           loadInfoArgs.parentOuterWindowID(),
                           loadInfoArgs.topOuterWindowID(),

--- a/netwerk/base/LoadInfo.cpp
+++ b/netwerk/base/LoadInfo.cpp
@@ -64,17 +64,16 @@ LoadInfo::LoadInfo(nsIPrincipal* aLoadin
   , mSecurityFlags(aSecurityFlags)
   , mInternalContentPolicyType(aContentPolicyType)
   , mTainting(LoadTainting::Basic)
   , mUpgradeInsecureRequests(false)
   , mBrowserUpgradeInsecureRequests(false)
   , mBrowserWouldUpgradeInsecureRequests(false)
   , mVerifySignedContent(false)
   , mEnforceSRI(false)
-  , mAllowDocumentToBeAgnosticToCSP(false)
   , mForceAllowDataURI(false)
   , mAllowInsecureRedirectToDataURI(false)
   , mSkipContentPolicyCheckForWebRequest(false)
   , mOriginalFrameSrcLoad(false)
   , mForceInheritPrincipalDropped(false)
   , mInnerWindowID(0)
   , mOuterWindowID(0)
   , mParentOuterWindowID(0)
@@ -291,17 +290,16 @@ LoadInfo::LoadInfo(nsPIDOMWindowOuter* a
   , mSecurityFlags(aSecurityFlags)
   , mInternalContentPolicyType(nsIContentPolicy::TYPE_DOCUMENT)
   , mTainting(LoadTainting::Basic)
   , mUpgradeInsecureRequests(false)
   , mBrowserUpgradeInsecureRequests(false)
   , mBrowserWouldUpgradeInsecureRequests(false)
   , mVerifySignedContent(false)
   , mEnforceSRI(false)
-  , mAllowDocumentToBeAgnosticToCSP(false)
   , mForceAllowDataURI(false)
   , mAllowInsecureRedirectToDataURI(false)
   , mSkipContentPolicyCheckForWebRequest(false)
   , mOriginalFrameSrcLoad(false)
   , mForceInheritPrincipalDropped(false)
   , mInnerWindowID(0)
   , mOuterWindowID(0)
   , mParentOuterWindowID(0)
@@ -370,17 +368,16 @@ LoadInfo::LoadInfo(const LoadInfo& rhs)
   , mSecurityFlags(rhs.mSecurityFlags)
   , mInternalContentPolicyType(rhs.mInternalContentPolicyType)
   , mTainting(rhs.mTainting)
   , mUpgradeInsecureRequests(rhs.mUpgradeInsecureRequests)
   , mBrowserUpgradeInsecureRequests(rhs.mBrowserUpgradeInsecureRequests)
   , mBrowserWouldUpgradeInsecureRequests(rhs.mBrowserWouldUpgradeInsecureRequests)
   , mVerifySignedContent(rhs.mVerifySignedContent)
   , mEnforceSRI(rhs.mEnforceSRI)
-  , mAllowDocumentToBeAgnosticToCSP(rhs.mAllowDocumentToBeAgnosticToCSP)
   , mForceAllowDataURI(rhs.mForceAllowDataURI)
   , mAllowInsecureRedirectToDataURI(rhs.mAllowInsecureRedirectToDataURI)
   , mSkipContentPolicyCheckForWebRequest(rhs.mSkipContentPolicyCheckForWebRequest)
   , mOriginalFrameSrcLoad(rhs.mOriginalFrameSrcLoad)
   , mForceInheritPrincipalDropped(rhs.mForceInheritPrincipalDropped)
   , mInnerWindowID(rhs.mInnerWindowID)
   , mOuterWindowID(rhs.mOuterWindowID)
   , mParentOuterWindowID(rhs.mParentOuterWindowID)
@@ -416,17 +413,16 @@ LoadInfo::LoadInfo(nsIPrincipal* aLoadin
                    nsSecurityFlags aSecurityFlags,
                    nsContentPolicyType aContentPolicyType,
                    LoadTainting aTainting,
                    bool aUpgradeInsecureRequests,
                    bool aBrowserUpgradeInsecureRequests,
                    bool aBrowserWouldUpgradeInsecureRequests,
                    bool aVerifySignedContent,
                    bool aEnforceSRI,
-                   bool aAllowDocumentToBeAgnosticToCSP,
                    bool aForceAllowDataURI,
                    bool aAllowInsecureRedirectToDataURI,
                    bool aSkipContentPolicyCheckForWebRequest,
                    bool aForceInheritPrincipalDropped,
                    uint64_t aInnerWindowID,
                    uint64_t aOuterWindowID,
                    uint64_t aParentOuterWindowID,
                    uint64_t aTopOuterWindowID,
@@ -456,17 +452,16 @@ LoadInfo::LoadInfo(nsIPrincipal* aLoadin
   , mSecurityFlags(aSecurityFlags)
   , mInternalContentPolicyType(aContentPolicyType)
   , mTainting(aTainting)
   , mUpgradeInsecureRequests(aUpgradeInsecureRequests)
   , mBrowserUpgradeInsecureRequests(aBrowserUpgradeInsecureRequests)
   , mBrowserWouldUpgradeInsecureRequests(aBrowserWouldUpgradeInsecureRequests)
   , mVerifySignedContent(aVerifySignedContent)
   , mEnforceSRI(aEnforceSRI)
-  , mAllowDocumentToBeAgnosticToCSP(aAllowDocumentToBeAgnosticToCSP)
   , mForceAllowDataURI(aForceAllowDataURI)
   , mAllowInsecureRedirectToDataURI(aAllowInsecureRedirectToDataURI)
   , mSkipContentPolicyCheckForWebRequest(aSkipContentPolicyCheckForWebRequest)
   , mOriginalFrameSrcLoad(false)
   , mForceInheritPrincipalDropped(aForceInheritPrincipalDropped)
   , mInnerWindowID(aInnerWindowID)
   , mOuterWindowID(aOuterWindowID)
   , mParentOuterWindowID(aParentOuterWindowID)
@@ -1003,35 +998,16 @@ LoadInfo::ResetPrincipalToInheritToNullP
   // any non null owner set on the channel and will return the principal
   // form the loadinfo instead.
   mSecurityFlags |= SEC_FORCE_INHERIT_PRINCIPAL_OVERRULE_OWNER;
 
   return NS_OK;
 }
 
 NS_IMETHODIMP
-LoadInfo::SetAllowDocumentToBeAgnosticToCSP(bool aAllowDocumentToBeAgnosticToCSP)
-{
-  if (mInternalContentPolicyType != nsIContentPolicy::TYPE_DOCUMENT) {
-    MOZ_ASSERT(false, "not available for loads other than TYPE_DOCUMENT");
-    return NS_ERROR_UNEXPECTED;
-  }
-  mAllowDocumentToBeAgnosticToCSP = aAllowDocumentToBeAgnosticToCSP;
-  return NS_OK;
-}
-
-NS_IMETHODIMP
-LoadInfo::GetAllowDocumentToBeAgnosticToCSP(bool* aAllowDocumentToBeAgnosticToCSP)
-{
-  *aAllowDocumentToBeAgnosticToCSP = mAllowDocumentToBeAgnosticToCSP;
-  return NS_OK;
-}
-
-
-NS_IMETHODIMP
 LoadInfo::SetScriptableOriginAttributes(JSContext* aCx,
   JS::Handle<JS::Value> aOriginAttributes)
 {
   OriginAttributes attrs;
   if (!aOriginAttributes.isObject() || !attrs.Init(aCx, aOriginAttributes)) {
     return NS_ERROR_INVALID_ARG;
   }
 

--- a/netwerk/base/LoadInfo.h
+++ b/netwerk/base/LoadInfo.h
@@ -113,17 +113,16 @@ private:
            nsSecurityFlags aSecurityFlags,
            nsContentPolicyType aContentPolicyType,
            LoadTainting aTainting,
            bool aUpgradeInsecureRequests,
            bool aBrowserUpgradeInsecureRequests,
            bool aBrowserWouldUpgradeInsecureRequests,
            bool aVerifySignedContent,
            bool aEnforceSRI,
-           bool aAllowDocumentToBeAgnosticToCSP,
            bool aForceAllowDataURI,
            bool aAllowInsecureRedirectToDataURI,
            bool aSkipContentPolicyCheckForWebRequest,
            bool aForceInheritPrincipalDropped,
            uint64_t aInnerWindowID,
            uint64_t aOuterWindowID,
            uint64_t aParentOuterWindowID,
            uint64_t aTopOuterWindowID,
@@ -182,17 +181,16 @@ private:
   nsSecurityFlags                  mSecurityFlags;
   nsContentPolicyType              mInternalContentPolicyType;
   LoadTainting                     mTainting;
   bool                             mUpgradeInsecureRequests;
   bool                             mBrowserUpgradeInsecureRequests;
   bool                             mBrowserWouldUpgradeInsecureRequests;
   bool                             mVerifySignedContent;
   bool                             mEnforceSRI;
-  bool                             mAllowDocumentToBeAgnosticToCSP;
   bool                             mForceAllowDataURI;
   bool                             mAllowInsecureRedirectToDataURI;
   bool                             mSkipContentPolicyCheckForWebRequest;
   bool                             mOriginalFrameSrcLoad;
   bool                             mForceInheritPrincipalDropped;
   uint64_t                         mInnerWindowID;
   uint64_t                         mOuterWindowID;
   uint64_t                         mParentOuterWindowID;

--- a/netwerk/base/nsILoadInfo.idl
+++ b/netwerk/base/nsILoadInfo.idl
@@ -623,28 +623,16 @@ interface nsILoadInfo : nsISupports
    * which inherits the origin attributes from the loadInfo.
    *
    * WARNING: Please only use that function if you know exactly what
    * you are doing!!!
    */
   void resetPrincipalToInheritToNullPrincipal();
 
   /**
-   * Allows certain top-level channels to be agnostic to CSP. If set,
-   * this attribute needs to be set before the CSP is initialized
-   * within nsDocument. If set after, this attribute has no effect.
-   * Please note, that this logic is only available for loads of TYPE_DOCUMENT,
-   * and is discarded for other loads.
-   *
-   * WARNING: Please only use that function if you know exactly what
-   * you are doing!!!
-   */
-  [infallible] attribute boolean allowDocumentToBeAgnosticToCSP;
-
-  /**
    * Customized OriginAttributes within LoadInfo to allow overwriting of the
    * default originAttributes from the loadingPrincipal.
    *
    * In chrome side, originAttributes.privateBrowsingId will always be 0 even if
    * the usePrivateBrowsing is true, because chrome docshell won't set
    * privateBrowsingId on origin attributes (See bug 1278664). This is to make
    * sure nsILoadInfo and nsILoadContext have the same origin attributes.
    */

--- a/netwerk/ipc/NeckoChannelParams.ipdlh
+++ b/netwerk/ipc/NeckoChannelParams.ipdlh
@@ -46,17 +46,16 @@ struct LoadInfoArgs
   uint32_t                    securityFlags;
   uint32_t                    contentPolicyType;
   uint32_t                    tainting;
   bool                        upgradeInsecureRequests;
   bool                        browserUpgradeInsecureRequests;
   bool                        browserWouldUpgradeInsecureRequests;
   bool                        verifySignedContent;
   bool                        enforceSRI;
-  bool                        allowDocumentToBeAgnosticToCSP;
   bool                        forceAllowDataURI;
   bool                        allowInsecureRedirectToDataURI;
   bool                        skipContentPolicyCheckForWebRequest;
   bool                        forceInheritPrincipalDropped;
   uint64_t                    innerWindowID;
   uint64_t                    outerWindowID;
   uint64_t                    parentOuterWindowID;
   uint64_t                    topOuterWindowID;