Bug 1466950 - Fix test to work on Android. r=hiro

MozReview-Commit-ID: G2NTiGUiw5Y

--HG--
extra : rebase_source : 149e87e81d115cbb1a1b1684e0022fc24f7a7eb5

dom/interfaces/base/nsIDOMWindowUtils.idl

@@ -1698,7 +1698,7 @@ interface nsIDOMWindowUtils : nsISupports {
                        [optional] in AString aPseudoElement);
 
   /*
-   * Returns the value of the transform value on the compositor thread.
+   * Returns the value of the transform on the compositor, in layer pixels.
    * Unlike the above getOMTAStyle, the transform value returned by this
    * includes both of animating and APZ values.
    * Note: This function doesn't work on WebRender at all.  Also this function

gfx/layers/Layers.cpp

@@ -592,6 +592,17 @@ Layer::HasScrollableFrameMetrics() const
   return false;
 }
 
+bool
+Layer::HasRootScrollableFrameMetrics() const
+{
+  for (uint32_t i = 0; i < GetScrollMetadataCount(); i++) {
+    if (GetFrameMetrics(i).IsScrollable() && GetFrameMetrics(i).IsRootContent()) {
+      return true;
+    }
+  }
+  return false;
+}
+
 bool
 Layer::IsScrollableWithoutContent() const
 {

gfx/layers/Layers.h

@@ -1292,6 +1292,7 @@ public:
   uint32_t GetScrollMetadataCount() const { return mScrollMetadata.Length(); }
   const nsTArray<ScrollMetadata>& GetAllScrollMetadata() { return mScrollMetadata; }
   bool HasScrollableFrameMetrics() const;
+  bool HasRootScrollableFrameMetrics() const;
   bool IsScrollableWithoutContent() const;
   const EventRegions& GetEventRegions() const { return mEventRegions; }
   ContainerLayer* GetParent() { return mParent; }

gfx/layers/apz/test/mochitest/helper_bug1464568_opacity.html

@@ -35,6 +35,7 @@ const utils = SpecialPowers.getDOMWindowUtils(window);
 async function test_opacity() {
   utils.setDisplayPortForElement(0, 0, 300, 1000, document.documentElement, 1);
   await promiseAllPaintsDone();
+  let dpr = window.devicePixelRatio;
 
   let transform = utils.getOMTCTransform(anim);
   is(transform, "matrix(1, 0, 0, 1, 0, 0)",
@@ -45,7 +46,7 @@ async function test_opacity() {
   await new Promise(resolve => waitForApzFlushedRepaints(resolve));
 
   transform = utils.getOMTCTransform(anim);
-  is(transform, "matrix(1, 0, 0, 1, 0, -300)",
+  is(transform, `matrix(1, 0, 0, 1, 0, ${-300 * dpr})`,
      "Element should have been moved by the offset");
 }
 

gfx/layers/apz/test/mochitest/helper_bug1464568_transform.html

@@ -36,8 +36,9 @@ async function test_transform() {
   utils.setDisplayPortForElement(0, 0, 300, 1000, document.documentElement, 1);
   await promiseAllPaintsDone();
 
+  let dpr = window.devicePixelRatio;
   let transform = utils.getOMTCTransform(anim);
-  is(transform, "matrix(1, 0, 0, 1, 200, 0)",
+  is(transform, `matrix(1, 0, 0, 1, ${200 * dpr}, 0)`,
      "The element shouldn't be moved before scrolling");
 
   utils.setAsyncScrollOffset(document.documentElement, 0, 300);
@@ -45,7 +46,7 @@ async function test_transform() {
   await new Promise(resolve => waitForApzFlushedRepaints(resolve));
 
   transform = utils.getOMTCTransform(anim);
-  is(transform, "matrix(1, 0, 0, 1, 200, -300)",
+  is(transform, `matrix(1, 0, 0, 1, ${200 * dpr}, ${-300 * dpr})`,
      "Element should have been moved by the offset");
 }
 

gfx/layers/apz/test/mochitest/mochitest.ini

@@ -15,7 +15,6 @@
 [test_bug1304689.html]
 [test_bug1304689-2.html]
 [test_bug1464568.html]
-  skip-if = (toolkit == 'android') # setAsyncScrollOffset doesn't work on mobile
 [test_frame_reconstruction.html]
 [test_group_mouseevents.html]
   skip-if = (toolkit == 'android') # mouse events not supported on mobile

gfx/layers/ipc/LayerTransactionParent.cpp

@@ -790,6 +790,17 @@ LayerTransactionParent::RecvGetTransform(const LayerHandle& aLayerHandle,
     transform.PostTranslate(-scaledOrigin.x, -scaledOrigin.y, -scaledOrigin.z);
   }
 
+  // This function is supposed to include the APZ transform, but if root scroll
+  // containers are enabled, then the APZ transform might not be on |layer| but
+  // instead would be on the parent of |layer|, if that is the root scrollable
+  // metrics. So we special-case that behaviour.
+  if (gfxPrefs::LayoutUseContainersForRootFrames() &&
+      !layer->HasScrollableFrameMetrics() &&
+      layer->GetParent() &&
+      layer->GetParent()->HasRootScrollableFrameMetrics()) {
+    transform *= layer->GetParent()->AsHostLayer()->GetShadowBaseTransform();
+  }
+
   *aTransform = transform;
 
   return IPC_OK();