From 4e485899748b7b6bbd6025f503ee3a3185bfa743 Mon Sep 17 00:00:00 2001
From: Sebastian Hengst <archaeopteryx@coole-files.de>
Date: Thu, 20 Jul 2017 15:39:48 +0200
Subject: [PATCH] Backed out changeset 1f1175528301 (bug 1380133)

---
 layout/style/nsStyleContext.cpp | 23 ++++++++++++++++++-----
 layout/style/nsStyleContext.h   |  7 +++++++
 2 files changed, 25 insertions(+), 5 deletions(-)

diff --git a/layout/style/nsStyleContext.cpp b/layout/style/nsStyleContext.cpp
index b50eda8eef43..8400857ad26e 100644
--- a/layout/style/nsStyleContext.cpp
+++ b/layout/style/nsStyleContext.cpp
@@ -185,13 +185,14 @@ nsStyleContext::MoveTo(nsStyleContext* aNewParent)
   }
 }
 
+template<class StyleContextLike>
 nsChangeHint
-nsStyleContext::CalcStyleDifference(nsStyleContext* aNewContext,
-                                    uint32_t* aEqualStructs,
-                                    uint32_t* aSamePointerStructs,
-                                    uint32_t aRelevantStructs)
+nsStyleContext::CalcStyleDifferenceInternal(StyleContextLike* aNewContext,
+                                            uint32_t* aEqualStructs,
+                                            uint32_t* aSamePointerStructs,
+                                            uint32_t aRelevantStructs)
 {
-  AUTO_PROFILER_LABEL("nsStyleContext::CalcStyleDifference", CSS);
+  AUTO_PROFILER_LABEL("nsStyleContext::CalcStyleDifferenceInternal", CSS);
 
   static_assert(nsStyleStructID_Length <= 32,
                 "aEqualStructs is not big enough");
@@ -446,6 +447,18 @@ nsStyleContext::CalcStyleDifference(nsStyleContext* aNewContext,
   return hint & ~nsChangeHint_NeutralChange;
 }
 
+nsChangeHint
+nsStyleContext::CalcStyleDifference(nsStyleContext* aNewContext,
+                                    uint32_t* aEqualStructs,
+                                    uint32_t* aSamePointerStructs,
+                                    uint32_t aRelevantStructs)
+{
+  return CalcStyleDifferenceInternal(aNewContext,
+                                     aEqualStructs,
+                                     aSamePointerStructs,
+                                     aRelevantStructs);
+}
+
 namespace mozilla {
 
 void
diff --git a/layout/style/nsStyleContext.h b/layout/style/nsStyleContext.h
index 44737f784f96..a9b8dbf88bc9 100644
--- a/layout/style/nsStyleContext.h
+++ b/layout/style/nsStyleContext.h
@@ -287,6 +287,13 @@ public:
                                    uint32_t aRelevantStructs =
                                      kAllResolvedStructs);
 
+private:
+  template<class StyleContextLike>
+  nsChangeHint CalcStyleDifferenceInternal(StyleContextLike* aNewContext,
+                                           uint32_t* aEqualStructs,
+                                           uint32_t* aSamePointerStructs,
+                                           uint32_t aRelevantStructs);
+
 public:
   /**
    * Get a color that depends on link-visitedness using this and