Refactor to centralize code which decides whether ObjectPaintProperties are needed.

third_party/WebKit/Source/core/paint/PaintPropertyTreeUpdateTests.cpp

Index: third_party/WebKit/Source/core/paint/PaintPropertyTreeUpdateTests.cpp
diff --git a/third_party/WebKit/Source/core/paint/PaintPropertyTreeUpdateTests.cpp b/third_party/WebKit/Source/core/paint/PaintPropertyTreeUpdateTests.cpp
index 9fdb15784eac0ec38aeca66984bdacdcc310d5f1..36327494b089d2e168868764dd70a9e505d3e188 100644
--- a/third_party/WebKit/Source/core/paint/PaintPropertyTreeUpdateTests.cpp
+++ b/third_party/WebKit/Source/core/paint/PaintPropertyTreeUpdateTests.cpp
@@ -552,7 +552,7 @@ TEST_P(PaintPropertyTreeUpdateTest,
   // Removing the animation should remove the transform node.
   target->removeAttribute(HTMLNames::classAttr);
   GetDocument().View()->UpdateAllLifecyclePhases();
-  EXPECT_EQ(nullptr, properties->Transform());
+  EXPECT_EQ(nullptr, target->GetLayoutObject()->PaintProperties());

[pdr., 2017/04/20 22:56:28]

Can you add a comment here so we don't accidentally refactor this away in the
future? Something like:
// Ensure the paint properties object was cleared as it is no longer needed.
(Or add a new test of the paint property clearing optimization)

[chrishtr, 2017/04/21 01:20:02]

Added comment.

 }
 
 TEST_P(PaintPropertyTreeUpdateTest,
@@ -566,7 +566,7 @@ TEST_P(PaintPropertyTreeUpdateTest,
   // Removing the animation should remove the effect node.
   target->removeAttribute(HTMLNames::classAttr);
   GetDocument().View()->UpdateAllLifecyclePhases();
-  EXPECT_EQ(nullptr, properties->Effect());
+  EXPECT_EQ(nullptr, target->GetLayoutObject()->PaintProperties());
 }
 
 TEST_P(PaintPropertyTreeUpdateTest,