Bug 1494408 - Clip groups to the transform clip to avoid bounds changes. r=jrmuizel

Differential Revision: https://phabricator.services.mozilla.com/D17983

--HG--
extra : moz-landing-system : lando

gfx/layers/wr/WebRenderCommandBuilder.cpp

@@ -1301,6 +1301,16 @@ void WebRenderCommandBuilder::DoGroupingForDisplayList(
 
   bool snapped;
   nsRect groupBounds = aWrappingItem->GetBounds(aDisplayListBuilder, &snapped);
+  // We don't want to restrict the size of the blob to the building rect of the
+  // display item, since that will change when we scroll and trigger a resize
+  // invalidation of the blob (will be fixed by blob recoordination).
+  // Instead we retrieve the bounds of the overflow clip on the <svg> and use
+  // that to restrict our size and prevent invisible content from affecting
+  // our bounds.
+  if (mClippedGroupBounds) {
+    groupBounds = groupBounds.Intersect(mClippedGroupBounds.value());
+    mClippedGroupBounds = Nothing();
+  }
   DIGroup& group = groupData->mSubGroup;
 
   gfx::Size scale = aSc.GetInheritedScale();
@@ -1485,7 +1495,8 @@ bool WebRenderCommandBuilder::ShouldDumpDisplayList(
 void WebRenderCommandBuilder::CreateWebRenderCommandsFromDisplayList(
     nsDisplayList* aDisplayList, nsDisplayItem* aWrappingItem,
     nsDisplayListBuilder* aDisplayListBuilder, const StackingContextHelper& aSc,
-    wr::DisplayListBuilder& aBuilder, wr::IpcResourceUpdateQueue& aResources) {
+    wr::DisplayListBuilder& aBuilder, wr::IpcResourceUpdateQueue& aResources,
+    nsDisplayItem* aOuterItem) {
   if (mDoGrouping) {
     MOZ_RELEASE_ASSERT(
         aWrappingItem,
@@ -1595,6 +1606,25 @@ void WebRenderCommandBuilder::CreateWebRenderCommandsFromDisplayList(
         // animated geometry root, so we can combine subsequent items of that
         // type into the same image.
         mContainsSVGGroup = mDoGrouping = true;
+        if (aOuterItem &&
+            aOuterItem->GetType() == DisplayItemType::TYPE_TRANSFORM) {
+          // Inline <svg> should always have an overflow clip, but it gets put
+          // outside the nsDisplayTransform we create for scaling the svg
+          // viewport. Converting the clip into inner coordinates lets us
+          // restrict the size of the blob images and prevents unnecessary
+          // resizes.
+          nsDisplayTransform* transform =
+              static_cast<nsDisplayTransform*>(aOuterItem);
+
+          nsRect clippedBounds =
+              transform->GetClippedBounds(aDisplayListBuilder);
+          nsRect innerClippedBounds;
+          DebugOnly<bool> result = transform->UntransformRect(
+              aDisplayListBuilder, clippedBounds, &innerClippedBounds);
+          MOZ_ASSERT(result);
+
+          mClippedGroupBounds = Some(innerClippedBounds);
+        }
         GP("attempting to enter the grouping code\n");
       }
 

gfx/layers/wr/WebRenderCommandBuilder.h

@@ -92,10 +92,11 @@ class WebRenderCommandBuilder {
                        nsDisplayListBuilder* aDisplayListBuilder);
 
   void CreateWebRenderCommandsFromDisplayList(
-      nsDisplayList* aDisplayList, nsDisplayItem* aOuterItem,
+      nsDisplayList* aDisplayList, nsDisplayItem* aWrappingItem,
       nsDisplayListBuilder* aDisplayListBuilder,
       const StackingContextHelper& aSc, wr::DisplayListBuilder& aBuilder,
-      wr::IpcResourceUpdateQueue& aResources);
+      wr::IpcResourceUpdateQueue& aResources,
+      nsDisplayItem* aOuterItem = nullptr);
 
   // aWrappingItem has to be non-null.
   void DoGroupingForDisplayList(nsDisplayList* aDisplayList,
@@ -201,6 +202,7 @@ class WebRenderCommandBuilder {
   // Whether consecutive inactive display items should be grouped into one
   // blob image.
   bool mDoGrouping;
+  Maybe<nsRect> mClippedGroupBounds;
 
   // True if we're currently within an opacity:0 container, and only
   // plugin and hit test items should be considered.

layout/painting/nsDisplayList.cpp

@@ -7896,8 +7896,10 @@ bool nsDisplayTransform::CreateWebRenderCommands(
                            params,
                            LayoutDeviceRect(position, LayoutDeviceSize()));
 
-  return mStoredList.CreateWebRenderCommands(aBuilder, aResources, sc, aManager,
+  aManager->CommandBuilder().CreateWebRenderCommandsFromDisplayList(
-                                             aDisplayListBuilder);
+      mStoredList.GetChildren(), &mStoredList, aDisplayListBuilder, sc,
+      aBuilder, aResources, this);
+  return true;
 }
 
 bool nsDisplayTransform::UpdateScrollData(

layout/reftests/svg/as-image/reftest.list

@@ -132,18 +132,18 @@ fuzzy-if(d2d,0-16,0-10) == img-content-outside-viewBox-1.html img-content-outsid
 
 == img-widthAndHeight-meet-1.html  img-widthAndHeight-meet-1-ref.html
 == img-widthAndHeight-meet-2.html  img-widthAndHeight-meet-2-ref.html
-fuzzy-if(webrender,255-255,21-21) == img-widthAndHeight-slice-1.html img-widthAndHeight-slice-1-ref.html
+== img-widthAndHeight-slice-1.html img-widthAndHeight-slice-1-ref.html
-fuzzy-if(webrender,255-255,12-12) == img-widthAndHeight-slice-2.html img-widthAndHeight-slice-2-ref.html
+== img-widthAndHeight-slice-2.html img-widthAndHeight-slice-2-ref.html
 
 == img-height-meet-1.html   img-height-meet-1-ref.html
 == img-height-meet-2.html   img-height-meet-2-ref.html
-fuzzy-if(webrender,255-255,21-21) == img-height-slice-1.html  img-height-slice-1-ref.html
+== img-height-slice-1.html  img-height-slice-1-ref.html
-fuzzy-if(webrender,255-255,12-12) == img-height-slice-2.html  img-height-slice-2-ref.html
+== img-height-slice-2.html  img-height-slice-2-ref.html
 
 == img-width-meet-1.html   img-width-meet-1-ref.html
 == img-width-meet-2.html   img-width-meet-2-ref.html
-fuzzy-if(webrender,255-255,21-21) == img-width-slice-1.html  img-width-slice-1-ref.html
+fuzzy-if(webrender,255-255,3-3) == img-width-slice-1.html  img-width-slice-1-ref.html
-fuzzy-if(webrender,255-255,12-12) == img-width-slice-2.html  img-width-slice-2-ref.html
+== img-width-slice-2.html  img-width-slice-2-ref.html
 
 # Alternate version of "width & height both non-%-valued" tests, but now
 # with no explicit viewBox, to trigger "synthesize-viewBox" behavior
@@ -154,10 +154,10 @@ fuzzy-if(webrender,255-255,12-12) == img-width-slice-2.html  img-width-slice-2-r
 
 # Alternate versions of "only one dimension is non-%-valued" tests, but now
 # with no explicit viewBox, to trigger "synthesize-viewBox" behavior
-fuzzy-if(webrender,255-255,20-40) == img-novb-height-meet-1.html    img-novb-height-all-1-ref.html
+== img-novb-height-meet-1.html    img-novb-height-all-1-ref.html
-fuzzy-if(webrender,255-255,20-40) == img-novb-height-slice-1.html   img-novb-height-all-1-ref.html
+== img-novb-height-slice-1.html   img-novb-height-all-1-ref.html
-fuzzy-if(skiaContent,0-255,0-10) fuzzy-if(webrender,255-255,20-20) == img-novb-width-meet-1.html     img-novb-width-all-1-ref.html
+fuzzy-if(skiaContent,0-255,0-10) == img-novb-width-meet-1.html     img-novb-width-all-1-ref.html
-fuzzy-if(skiaContent,0-255,0-10) fuzzy-if(webrender,255-255,20-20) == img-novb-width-slice-1.html    img-novb-width-all-1-ref.html
+fuzzy-if(skiaContent,0-255,0-10) == img-novb-width-slice-1.html    img-novb-width-all-1-ref.html
 
 # with with a fragmentIdentifier viewBox
 == img-fragment-1a.html  img-fragment-1-ref.html

layout/reftests/svg/smil/transform/reftest.list

@@ -3,7 +3,7 @@
 
 fuzzy(0-111,0-1802) fuzzy-if(skiaContent,0-130,0-1000) == additive-1.svg additive-1-ref.svg # bug 981344, bug 1239766
 == animate-width-1.svg lime.svg
-fuzzy-if(cocoaWidget,0-3,0-50) fuzzy-if(winWidget,0-15,0-30) fuzzy-if(gtkWidget,0-3,0-50) fuzzy-if(webrender,3-3,9-9) fuzzy-if(Android,0-16,0-1) == paced-1.svg paced-1-ref.svg # bug 981640, Bug 1293550
+fuzzy-if(cocoaWidget,0-3,0-50) fuzzy-if(winWidget,0-15,0-30) fuzzy-if(gtkWidget,0-3,0-50) fuzzy-if(Android,0-16,0-1) == paced-1.svg paced-1-ref.svg # bug 981640, Bug 1293550
 fuzzy-if(skiaContent,0-7,0-90) == rotate-angle-1.svg rotate-angle-ref.svg
 fuzzy-if(skiaContent,0-7,0-90) == rotate-angle-2.svg rotate-angle-ref.svg
 fuzzy-if(skiaContent,0-7,0-130) == rotate-angle-3.svg rotate-angle-ref.svg