Bug 1610731 - Incorporate the top/bottom margins set by reftests. r=botond

This makes the existing test for this codepath start passing on geckoview-qr.

Differential Revision: https://phabricator.services.mozilla.com/D69558

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

gfx/layers/apz/src/APZCTreeManager.cpp

@@ -817,7 +817,8 @@ void APZCTreeManager::SampleForWebRender(
     if (info.mScrollDirection == ScrollDirection::eHorizontal) {
       ScreenPoint translation =
           AsyncCompositionManager::ComputeFixedMarginsOffset(
-              mCompositorFixedLayerMargins, SideBits::eBottom, ScreenMargin());
+              GetCompositorFixedLayerMargins(), SideBits::eBottom,
+              ScreenMargin());
 
       LayerToParentLayerMatrix4x4 transform =
           LayerToParentLayerMatrix4x4::Translation(ViewAs<ParentLayerPixel>(
@@ -831,7 +832,7 @@ void APZCTreeManager::SampleForWebRender(
   for (const FixedPositionInfo& info : mFixedPositionInfo) {
     ScreenPoint translation =
         AsyncCompositionManager::ComputeFixedMarginsOffset(
-            mCompositorFixedLayerMargins, info.mFixedPosSides,
+            GetCompositorFixedLayerMargins(), info.mFixedPosSides,
             mGeckoFixedLayerMargins);
 
     LayerToParentLayerMatrix4x4 transform =
@@ -2085,7 +2086,7 @@ APZEventResult APZCTreeManager::ProcessTouchInput(MultiTouchInput& aInput) {
           MutexAutoLock lock(mMapLock);
           touchData.mScreenPoint -=
               RoundedToInt(AsyncCompositionManager::ComputeFixedMarginsOffset(
-                  mCompositorFixedLayerMargins, mFixedPosSidesForInputBlock,
+                  GetCompositorFixedLayerMargins(), mFixedPosSidesForInputBlock,
                   mGeckoFixedLayerMargins));
         }
       }
@@ -3373,7 +3374,7 @@ Maybe<ScreenIntPoint> APZCTreeManager::ConvertToGecko(
       MutexAutoLock mapLock(mMapLock);
       *geckoPoint -=
           RoundedToInt(AsyncCompositionManager::ComputeFixedMarginsOffset(
-              mCompositorFixedLayerMargins, mFixedPosSidesForInputBlock,
+              GetCompositorFixedLayerMargins(), mFixedPosSidesForInputBlock,
               mGeckoFixedLayerMargins));
     }
   }
@@ -3447,8 +3448,8 @@ bool APZCTreeManager::IsStuckToRootContentAtBottom(
     return false;
   }
 
-  // Currently we only support the dyanmic toolbar at bottom.
-  if ((aNode->GetFixedPosSides() & SideBits::eBottom) == SideBits::eNone) {
+  // We support the dynamic toolbar at top and bottom.
+  if ((aNode->GetFixedPosSides() & SideBits::eTopBottom) == SideBits::eNone) {
     return false;
   }
 
@@ -3543,7 +3544,7 @@ LayerToParentLayerMatrix4x4 APZCTreeManager::ComputeTransformForNode(
       MutexAutoLock mapLock(mMapLock);
       translation = ViewAs<ParentLayerPixel>(
           AsyncCompositionManager::ComputeFixedMarginsOffset(
-              mCompositorFixedLayerMargins, aNode->GetFixedPosSides(),
+              GetCompositorFixedLayerMargins(), aNode->GetFixedPosSides(),
               mGeckoFixedLayerMargins),
           PixelCastJustification::ScreenIsParentLayerForRoot);
     }
@@ -3556,8 +3557,8 @@ LayerToParentLayerMatrix4x4 APZCTreeManager::ComputeTransformForNode(
       MutexAutoLock mapLock(mMapLock);
       translation = ViewAs<ParentLayerPixel>(
           AsyncCompositionManager::ComputeFixedMarginsOffset(
-              mCompositorFixedLayerMargins,
-              aNode->GetFixedPosSides() & SideBits::eBottom,
+              GetCompositorFixedLayerMargins(),
+              aNode->GetFixedPosSides() & SideBits::eTopBottom,
               // For sticky layers, we don't need to factor
               // mGeckoFixedLayerMargins because Gecko doesn't shift the
               // position of sticky elements for dynamic toolbar movements.
@@ -3606,6 +3607,16 @@ already_AddRefed<GeckoContentController> APZCTreeManager::GetContentController(
   return controller.forget();
 }
 
+ScreenMargin APZCTreeManager::GetCompositorFixedLayerMargins() const {
+  RecursiveMutexAutoLock lock(mTreeLock);
+  ScreenMargin result = mCompositorFixedLayerMargins;
+  if (StaticPrefs::apz_fixed_margin_override_enabled()) {
+    result.top = StaticPrefs::apz_fixed_margin_override_top();
+    result.bottom = StaticPrefs::apz_fixed_margin_override_bottom();
+  }
+  return result;
+}
+
 bool APZCTreeManager::GetAPZTestData(LayersId aLayersId,
                                      APZTestData* aOutData) {
   AssertOnUpdaterThread();

gfx/layers/apz/src/APZCTreeManager.h

@@ -766,6 +766,8 @@ class APZCTreeManager : public IAPZCTreeManager, public APZInputBridge {
       const MutexAutoLock& aProofOfMapLock,
       ClippedCompositionBoundsMap& aDestMap, ScrollableLayerGuid aGuid);
 
+  ScreenMargin GetCompositorFixedLayerMargins() const;
+
  protected:
   /* The input queue where input events are held until we know enough to
    * figure out where they're going. Protected so gtests can access it.

layout/reftests/async-scrolling/reftest.list

@@ -98,4 +98,4 @@ fuzzy-if(!webrender,111-112,600-600) pref(apz.allow_zooming,true) == async-scrol
 
 # for this test, apz.allow_zooming is needed to ensure we take the containerless scrolling codepath that creates
 # an async zoom container (since we are testing a regression in that codepath)
-skip-if(!Android) pref(apz.allow_zooming,true) test-pref(apz.fixed-margin-override.enabled,true) test-pref(apz.fixed-margin-override.bottom,50) fails-if(geckoview&&webrender) == dynamic-toolbar-fixed-bottom-1.html dynamic-toolbar-fixed-bottom-1-ref.html
+skip-if(!Android) pref(apz.allow_zooming,true) test-pref(apz.fixed-margin-override.enabled,true) test-pref(apz.fixed-margin-override.bottom,50) == dynamic-toolbar-fixed-bottom-1.html dynamic-toolbar-fixed-bottom-1-ref.html