Rewrite how paint properties are built with bg:fixed main thread scrolling

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

 // Copyright 2016 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/paint/PaintPropertyTreeBuilderTest.h"
 #include "core/paint/PaintPropertyTreePrinter.h"
 
 namespace blink {
 
@@ skipping 72 matching lines @@
       "</div>"
       "<div class='forceScroll'></div>");
   Element* overflowA = document().getElementById("overflowA");
   Element* overflowB = document().getElementById("overflowB");
 
   EXPECT_TRUE(frameScroll()->hasBackgroundAttachmentFixedDescendants());
   EXPECT_TRUE(overflowA->layoutObject()
                   ->paintProperties()
                   ->scroll()
                   ->hasBackgroundAttachmentFixedDescendants());
-  EXPECT_FALSE(overflowB->layoutObject()
-                   ->paintProperties()
-                   ->scroll()
-                   ->hasBackgroundAttachmentFixedDescendants());
+  EXPECT_TRUE(overflowB->layoutObject()
+                  ->paintProperties()
+                  ->scroll()
+                  ->hasBackgroundAttachmentFixedDescendants());
 
   // Removing a main thread scrolling reason should update the entire tree.
   overflowB->removeAttribute("class");
   document().view()->updateAllLifecyclePhases();
   EXPECT_FALSE(frameScroll()->hasBackgroundAttachmentFixedDescendants());
   EXPECT_FALSE(overflowA->layoutObject()
                    ->paintProperties()
                    ->scroll()
                    ->hasBackgroundAttachmentFixedDescendants());
   EXPECT_FALSE(overflowB->layoutObject()
                    ->paintProperties()
                    ->scroll()
                    ->hasBackgroundAttachmentFixedDescendants());
 
   // Adding a main thread scrolling reason should update the entire tree.
   overflowB->setAttribute(HTMLNames::classAttr, "backgroundAttachmentFixed");
   document().view()->updateAllLifecyclePhases();
   EXPECT_TRUE(frameScroll()->hasBackgroundAttachmentFixedDescendants());
   EXPECT_TRUE(overflowA->layoutObject()
                   ->paintProperties()
                   ->scroll()
                   ->hasBackgroundAttachmentFixedDescendants());
-  EXPECT_FALSE(overflowB->layoutObject()
-                   ->paintProperties()
-                   ->scroll()
-                   ->hasBackgroundAttachmentFixedDescendants());
+  EXPECT_TRUE(overflowB->layoutObject()
+                  ->paintProperties()
+                  ->scroll()
+                  ->hasBackgroundAttachmentFixedDescendants());
+}
+
+TEST_P(PaintPropertyTreeUpdateTest, ParentFrameMainThreadScrollReasons) {
+  setBodyInnerHTML(
+      "<style>"
+      "  body { margin: 0; }"
+      "  .fixedBackground {"
+      "    background-image: url('foo');"
+      "    background-attachment: fixed;"
+      "  }"
+      "</style>"
+      "<iframe></iframe>"
+      "<div id='fixedBackground' class='fixedBackground'></div>"
+      "<div id='forceScroll' style='height: 8888px;'></div>");
+  setChildFrameHTML(
+      "<style>body { margin: 0; }</style>"
+      "<div id='forceScroll' style='height: 8888px;'></div>");
+  document().view()->updateAllLifecyclePhases();
+
+  FrameView* parent = document().view();
+  EXPECT_TRUE(frameScroll(parent)->hasBackgroundAttachmentFixedDescendants());
+  FrameView* child = childDocument().view();
+  EXPECT_TRUE(frameScroll(child)->hasBackgroundAttachmentFixedDescendants());
+
+  // Removing a main thread scrolling reason should update the entire tree.
+  auto* fixedBackground = document().getElementById("fixedBackground");
+  fixedBackground->removeAttribute(HTMLNames::classAttr);
+  document().view()->updateAllLifecyclePhases();
+  EXPECT_FALSE(frameScroll(parent)->hasBackgroundAttachmentFixedDescendants());
+  EXPECT_FALSE(frameScroll(child)->hasBackgroundAttachmentFixedDescendants());
+
+  // Adding a main thread scrolling reason should update the entire tree.
+  fixedBackground->setAttribute(HTMLNames::classAttr, "fixedBackground");
+  document().view()->updateAllLifecyclePhases();
+  EXPECT_TRUE(frameScroll(parent)->hasBackgroundAttachmentFixedDescendants());
+  EXPECT_TRUE(frameScroll(child)->hasBackgroundAttachmentFixedDescendants());
+}
+
+TEST_P(PaintPropertyTreeUpdateTest, ChildFrameMainThreadScrollReasons) {
+  setBodyInnerHTML(
+      "<style>body { margin: 0; }</style>"
+      "<iframe></iframe>"
+      "<div id='forceScroll' style='height: 8888px;'></div>");
+  setChildFrameHTML(
+      "<style>"
+      "  body { margin: 0; }"
+      "  .fixedBackground {"
+      "    background-image: url('foo');"
+      "    background-attachment: fixed;"
+      "  }"
+      "</style>"
+      "<div id='fixedBackground' class='fixedBackground'></div>"
+      "<div id='forceScroll' style='height: 8888px;'></div>");
+  document().view()->updateAllLifecyclePhases();
+
+  FrameView* parent = document().view();
+  EXPECT_FALSE(frameScroll(parent)->hasBackgroundAttachmentFixedDescendants());
+  FrameView* child = childDocument().view();
+  EXPECT_TRUE(frameScroll(child)->hasBackgroundAttachmentFixedDescendants());
+
+  // Removing a main thread scrolling reason should update the entire tree.
+  auto* fixedBackground = childDocument().getElementById("fixedBackground");
+  fixedBackground->removeAttribute(HTMLNames::classAttr);
+  document().view()->updateAllLifecyclePhases();
+  EXPECT_FALSE(frameScroll(parent)->hasBackgroundAttachmentFixedDescendants());
+  EXPECT_FALSE(frameScroll(child)->hasBackgroundAttachmentFixedDescendants());
+
+  // Adding a main thread scrolling reason should update the entire tree.
+  fixedBackground->setAttribute(HTMLNames::classAttr, "fixedBackground");
+  document().view()->updateAllLifecyclePhases();
+  EXPECT_FALSE(frameScroll(parent)->hasBackgroundAttachmentFixedDescendants());
+  EXPECT_TRUE(frameScroll(child)->hasBackgroundAttachmentFixedDescendants());
 }
 
 TEST_P(PaintPropertyTreeUpdateTest,
        BackgroundAttachmentFixedMainThreadScrollReasonsWithFixedScroller) {
   setBodyInnerHTML(
       "<style>"
       "  #overflowA {"
       "    position: absolute;"
       "    overflow: scroll;"
       "    width: 20px;"
@@ skipping 422 matching lines @@
   EXPECT_EQ(TransformationMatrix().translate3d(50, 100, 0),
             transformObject->paintProperties()->transform()->matrix());
 
   transform->setAttribute(HTMLNames::styleAttr, "width: 200px; height: 300px;");
   document().view()->updateAllLifecyclePhases();
   EXPECT_EQ(TransformationMatrix().translate3d(100, 150, 0),
             transformObject->paintProperties()->transform()->matrix());
 }
 
 }  // namespace blink