From faa7a6f3cbce42fc6e09b6794e1e67b74b8037d5 Mon Sep 17 00:00:00 2001
From: Hiroyuki Ikezoe <hikezoe@mozilla.com>
Date: Fri, 17 Mar 2017 12:48:51 +0900
Subject: [PATCH] Bug 1340958 - Allocate StyleRule only if we need to compose
 styles. r=birtles

MozReview-Commit-ID: 6ucsxBAaYRp

--HG--
extra : rebase_source : ec0bd4627d40335c353b79720f7dfb2e4f3c304c
---
 dom/animation/KeyframeEffectReadOnly.cpp | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/dom/animation/KeyframeEffectReadOnly.cpp b/dom/animation/KeyframeEffectReadOnly.cpp
index f32252ceb6e0..486dbe9c0919 100644
--- a/dom/animation/KeyframeEffectReadOnly.cpp
+++ b/dom/animation/KeyframeEffectReadOnly.cpp
@@ -440,7 +440,7 @@ KeyframeEffectReadOnly::GetUnderlyingStyle(
 {
   StyleAnimationValue result;
 
-  if (aAnimationRule->HasValue(aProperty)) {
+  if (aAnimationRule && aAnimationRule->HasValue(aProperty)) {
     // If we have already composed style for the property, we use the style
     // as the underlying style.
     DebugOnly<bool> success = aAnimationRule->GetValue(aProperty, result);
@@ -623,11 +623,6 @@ KeyframeEffectReadOnly::ComposeStyle(
     } else {
       // Gecko backend
 
-      if (!aStyleRule.mGecko) {
-        // Allocate the style rule now that we know we have animation data.
-        aStyleRule.mGecko = new AnimValuesStyleRule();
-      }
-
       StyleAnimationValue fromValue =
         CompositeValue(prop.mProperty, aStyleRule.mGecko,
                        segment->mFromValue.mGecko,
@@ -640,6 +635,11 @@ KeyframeEffectReadOnly::ComposeStyle(
         continue;
       }
 
+      if (!aStyleRule.mGecko) {
+        // Allocate the style rule now that we know we have animation data.
+        aStyleRule.mGecko = new AnimValuesStyleRule();
+      }
+
       // Iteration composition for accumulate
       if (mEffectOptions.mIterationComposite ==
           IterationCompositeOperation::Accumulate &&