Set a direct compositing reason for 3D transform & will-change property tree nodes

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

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/html/HTMLIFrameElement.h"
 #include "core/layout/LayoutTestHelper.h"
 #include "core/layout/LayoutTreeAsText.h"
 #include "core/layout/api/LayoutViewItem.h"
 #include "core/paint/ObjectPaintProperties.h"
 #include "core/paint/PaintPropertyTreePrinter.h"
@@ skipping 316 matching lines @@
       inner->layoutObject()->paintProperties();
   EXPECT_EQ(TransformationMatrix().translate(50, 100),
             innerProperties->paintOffsetTranslation()->matrix());
   EXPECT_EQ(perspectiveProperties->perspective(),
             innerProperties->paintOffsetTranslation()->parent());
   CHECK_EXACT_VISUAL_RECT(LayoutRect(50, 100, 100, 200), inner->layoutObject(),
                           document().view()->layoutView());
 }
 
 TEST_P(PaintPropertyTreeBuilderTest, Transform) {
-  loadTestData("transform.html");
+  setBodyInnerHTML(
+      "<style> body { margin: 0 } </style>"

[chrishtr, 2016/12/13 23:35:35]

I inlined this for imrpoved clarity and to be like most of the tests
in this file. If you agree, can change the rest o the loadTestData()
instances in another patch.

+      "<div id='transform' style='margin-left: 50px; margin-top: 100px;"
+      "    width: 400px; height: 300px;"
+      "    transform: translate3D(123px, 456px, 789px)'>"
+      "</div>");
 
   Element* transform = document().getElementById("transform");
   const ObjectPaintProperties* transformProperties =
       transform->layoutObject()->paintProperties();
   EXPECT_EQ(TransformationMatrix().translate3d(123, 456, 789),
             transformProperties->transform()->matrix());
   EXPECT_EQ(FloatPoint3D(200, 150, 0),
             transformProperties->transform()->origin());
   EXPECT_EQ(transformProperties->paintOffsetTranslation(),
             transformProperties->transform()->parent());
   EXPECT_EQ(TransformationMatrix().translate(50, 100),
             transformProperties->paintOffsetTranslation()->matrix());
   EXPECT_EQ(frameScrollTranslation(),
             transformProperties->paintOffsetTranslation()->parent());
+
+  EXPECT_TRUE(transformProperties->transform()->hasDirectCompositingReasons());
+  EXPECT_FALSE(frameScrollTranslation()->hasDirectCompositingReasons());
+
   CHECK_EXACT_VISUAL_RECT(LayoutRect(173, 556, 400, 300),
                           transform->layoutObject(),
                           document().view()->layoutView());
 }
 
 TEST_P(PaintPropertyTreeBuilderTest, RelativePositionInline) {
   loadTestData("relative-position-inline.html");
 
   Element* inlineBlock = document().getElementById("inline-block");
   const ObjectPaintProperties* inlineBlockProperties =
@@ skipping 2781 matching lines @@
   setBodyInnerHTML("<div id='div' style='background-color: blue'>DIV</div>");
   auto* div = document().getElementById("div");
 
   document().view()->updateAllLifecyclePhases();
   div->setAttribute(HTMLNames::styleAttr, "background-color: green");
   document().view()->updateLifecycleToLayoutClean();
   EXPECT_FALSE(div->layoutObject()->needsPaintPropertyUpdate());
 }
 
 }  // namespace blink