From 7d314b5011ad2f3631d775d5d6a2eef70a8565cf Mon Sep 17 00:00:00 2001
From: Ehsan Akhgari <ehsan@mozilla.com>
Date: Thu, 9 Aug 2018 11:56:45 -0400
Subject: [PATCH] Bug 1482129 - Exempt stylesheets, fonts and images when
 canceling loading of slow HTTP requests of tracking resources; r=valentin

---
 dom/base/nsIContentPolicy.idl           |  9 ++++----
 netwerk/protocol/http/nsHttpChannel.cpp | 29 ++++++++++++++++++++++++-
 2 files changed, 33 insertions(+), 5 deletions(-)

diff --git a/dom/base/nsIContentPolicy.idl b/dom/base/nsIContentPolicy.idl
index eddc89f64a91..511b7d010c97 100644
--- a/dom/base/nsIContentPolicy.idl
+++ b/dom/base/nsIContentPolicy.idl
@@ -348,10 +348,11 @@ interface nsIContentPolicy : nsISupports
 
   /* When adding new content types, please update nsContentBlocker,
    * NS_CP_ContentTypeName, nsCSPContext, CSP_ContentTypeToDirective,
-   * DoContentSecurityChecks, all nsIContentPolicy implementations, the
-   * static_assert in dom/cache/DBSchema.cpp, ChannelWrapper.webidl,
-   * ChannelWrapper.cpp, nsPermissionManager.cpp, and other things that are not
-   * listed here that are related to nsIContentPolicy. */
+   * DoContentSecurityChecks, IsContentPolicyTypeWhitelistedForFastBlock,
+   * all nsIContentPolicy implementations, the static_assert in
+   * dom/cache/DBSchema.cpp, ChannelWrapper.webidl, ChannelWrapper.cpp,
+   * nsPermissionManager.cpp, and other things that are not listed here
+   * that are related to nsIContentPolicy. */
 
   //////////////////////////////////////////////////////////////////////
 
diff --git a/netwerk/protocol/http/nsHttpChannel.cpp b/netwerk/protocol/http/nsHttpChannel.cpp
index 95527eb38312..14d2efcc69a7 100644
--- a/netwerk/protocol/http/nsHttpChannel.cpp
+++ b/netwerk/protocol/http/nsHttpChannel.cpp
@@ -596,6 +596,31 @@ nsHttpChannel::Connect()
     return ConnectOnTailUnblock();
 }
 
+static bool
+IsContentPolicyTypeWhitelistedForFastBlock(nsILoadInfo* aLoadInfo)
+{
+  nsContentPolicyType type = aLoadInfo ?
+                             aLoadInfo->GetExternalContentPolicyType() :
+                             nsIContentPolicy::TYPE_OTHER;
+  switch (type) {
+  // images
+  case nsIContentPolicy::TYPE_IMAGE:
+  case nsIContentPolicy::TYPE_IMAGESET:
+  case nsIContentPolicy::TYPE_INTERNAL_IMAGE:
+  case nsIContentPolicy::TYPE_INTERNAL_IMAGE_PRELOAD:
+  case nsIContentPolicy::TYPE_INTERNAL_IMAGE_FAVICON:
+  // fonts
+  case nsIContentPolicy::TYPE_FONT:
+  // stylesheets
+  case nsIContentPolicy::TYPE_STYLESHEET:
+  case nsIContentPolicy::TYPE_INTERNAL_STYLESHEET:
+  case nsIContentPolicy::TYPE_INTERNAL_STYLESHEET_PRELOAD:
+    return true;
+  default:
+    return false;
+  }
+}
+
 bool
 nsHttpChannel::CheckFastBlocked()
 {
@@ -616,7 +641,9 @@ nsHttpChannel::CheckFastBlocked()
         return false;
     }
 
-    if (!sIsFastBlockEnabled || !timestamp) {
+    if (!sIsFastBlockEnabled ||
+        IsContentPolicyTypeWhitelistedForFastBlock(mLoadInfo) ||
+        !timestamp) {
         return false;
     }