From cfab4c8f59fc81cbe9f0e0e7d7cc2703755448e3 Mon Sep 17 00:00:00 2001
From: Tobias Schneider <schneider@jancona.com>
Date: Tue, 20 Jun 2017 16:43:17 -0700
Subject: [PATCH] Bug 1363650 - (intersection-observer) Use content area as the
 intersection rectangle for custom root with overflow clip. r=mattwoodrow

--HG--
extra : rebase_source : 28c2af53622e02a2e46f49cd0aed642522d86937
---
 dom/base/DOMIntersectionObserver.cpp           | 18 +++++++++++-------
 .../containing-block.html.ini                  |  1 -
 .../remove-element.html.ini                    |  1 -
 .../same-document-root.html.ini                |  1 -
 4 files changed, 11 insertions(+), 10 deletions(-)

diff --git a/dom/base/DOMIntersectionObserver.cpp b/dom/base/DOMIntersectionObserver.cpp
index 82badf709e63..3db65c3f0681 100644
--- a/dom/base/DOMIntersectionObserver.cpp
+++ b/dom/base/DOMIntersectionObserver.cpp
@@ -268,17 +268,21 @@ DOMIntersectionObserver::Update(nsIDocument* aDocument, DOMHighResTimeStamp time
     root = mRoot;
     rootFrame = root->GetPrimaryFrame();
     if (rootFrame) {
+      nsRect rootRectRelativeToRootFrame;
       if (rootFrame->IsScrollFrame()) {
+        // rootRectRelativeToRootFrame should be the content rect of rootFrame, not including the scrollbars.
         nsIScrollableFrame* scrollFrame = do_QueryFrame(rootFrame);
-        rootRect = nsLayoutUtils::TransformFrameRectToAncestor(
-          rootFrame,
-          rootFrame->GetContentRectRelativeToSelf(),
-          scrollFrame->GetScrolledFrame());
+        rootRectRelativeToRootFrame = scrollFrame->GetScrollPortRect();
       } else {
-        rootRect = nsLayoutUtils::GetAllInFlowRectsUnion(rootFrame,
-          nsLayoutUtils::GetContainingBlockForClientRect(rootFrame),
-          nsLayoutUtils::RECTS_ACCOUNT_FOR_TRANSFORMS);
+        // rootRectRelativeToRootFrame should be the content rect of rootFrame.
+        rootRectRelativeToRootFrame = rootFrame->GetContentRectRelativeToSelf();
       }
+      nsIFrame* containingBlock =
+        nsLayoutUtils::GetContainingBlockForClientRect(rootFrame);
+      rootRect =
+        nsLayoutUtils::TransformFrameRectToAncestor(rootFrame,
+                                                    rootRectRelativeToRootFrame,
+                                                    containingBlock);
     }
   } else {
     nsCOMPtr<nsIPresShell> presShell = aDocument->GetShell();
diff --git a/testing/web-platform/meta/intersection-observer/containing-block.html.ini b/testing/web-platform/meta/intersection-observer/containing-block.html.ini
index 8a43c8f9c51f..0c70e062bfd5 100644
--- a/testing/web-platform/meta/intersection-observer/containing-block.html.ini
+++ b/testing/web-platform/meta/intersection-observer/containing-block.html.ini
@@ -1,3 +1,2 @@
 [containing-block.html]
   type: testharness
-  disabled: https://bugzilla.mozilla.org/show_bug.cgi?id=1363650
diff --git a/testing/web-platform/meta/intersection-observer/remove-element.html.ini b/testing/web-platform/meta/intersection-observer/remove-element.html.ini
index 3f2bff467631..5ac13ed03b2c 100644
--- a/testing/web-platform/meta/intersection-observer/remove-element.html.ini
+++ b/testing/web-platform/meta/intersection-observer/remove-element.html.ini
@@ -1,3 +1,2 @@
 [remove-element.html]
   type: testharness
-  disabled: https://bugzilla.mozilla.org/show_bug.cgi?id=1363650
diff --git a/testing/web-platform/meta/intersection-observer/same-document-root.html.ini b/testing/web-platform/meta/intersection-observer/same-document-root.html.ini
index 7fa7dfbed932..f834a3c8c18e 100644
--- a/testing/web-platform/meta/intersection-observer/same-document-root.html.ini
+++ b/testing/web-platform/meta/intersection-observer/same-document-root.html.ini
@@ -1,3 +1,2 @@
 [same-document-root.html]
   type: testharness
-  disabled: https://bugzilla.mozilla.org/show_bug.cgi?id=1363650