Bug 1496843. Make sure we update mRect when mImageBounds changes. r=mattwoodrow

This makes sure we don't end up with stale entries with geometry clipped
to the previous mImageBounds on the receiving side.

The update code is duplicated for now but will hopefully be cleaned up
after the blob re-coordination work is done.

Differential Revision: https://phabricator.services.mozilla.com/D11566

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

gfx/layers/wr/WebRenderCommandBuilder.cpp

@@ -549,18 +549,45 @@ struct DIGroup
             aData->mRect = transformedRect.Intersect(mImageBounds);
             InvalidateRect(aData->mRect);
             GP("UpdateContainerLayerPropertiesAndDetectChange change\n");
+          } else if (!aData->mImageRect.IsEqualEdges(mImageBounds)) {
+            // Make sure we update mRect for mImageBounds changes
+            combined = clip.ApplyNonRoundedIntersection(geometry->ComputeInvalidationRegion());
+            IntRect transformedRect = ToDeviceSpace(combined.GetBounds(), aMatrix, appUnitsPerDevPixel, mLayerBounds.TopLeft());
+            // The invalid rect should contain the old rect and the new rect
+            // because the parent should have invalidated this area
+            MOZ_RELEASE_ASSERT(mInvalidRect.Contains(aData->mRect));
+            aData->mRect = transformedRect.Intersect(mImageBounds);
+            MOZ_RELEASE_ASSERT(mInvalidRect.Contains(aData->mRect));
+            GP("ContainerLayer image rect bounds change\n");
           } else {
             // XXX: this code can eventually be deleted/made debug only
             combined = clip.ApplyNonRoundedIntersection(geometry->ComputeInvalidationRegion());
+            IntRect transformedRect = ToDeviceSpace(combined.GetBounds(), aMatrix, appUnitsPerDevPixel, mLayerBounds.TopLeft());
+            auto rect = transformedRect.Intersect(mImageBounds);
             GP("Layer NoChange: %s %d %d %d %d\n", aItem->Name(),
                    aData->mRect.x, aData->mRect.y, aData->mRect.XMost(), aData->mRect.YMost());
+            MOZ_RELEASE_ASSERT(rect.IsEqualEdges(aData->mRect));
           }
+        } else if (!aData->mImageRect.IsEqualEdges(mImageBounds)) {
+          // Make sure we update mRect for mImageBounds changes
+          UniquePtr<nsDisplayItemGeometry> geometry(aItem->AllocateGeometry(aBuilder));
+          combined = clip.ApplyNonRoundedIntersection(geometry->ComputeInvalidationRegion());
+          IntRect transformedRect = ToDeviceSpace(combined.GetBounds(), aMatrix, appUnitsPerDevPixel, mLayerBounds.TopLeft());
+          // The invalid rect should contain the old rect and the new rect
+          // because the parent should have invalidated this area
+          MOZ_RELEASE_ASSERT(mInvalidRect.Contains(aData->mRect));
+          aData->mRect = transformedRect.Intersect(mImageBounds);
+          MOZ_RELEASE_ASSERT(mInvalidRect.Contains(aData->mRect));
+          GP("image rect bounds change\n");
         } else {
           // XXX: this code can eventually be deleted/made debug only
           UniquePtr<nsDisplayItemGeometry> geometry(aItem->AllocateGeometry(aBuilder));
           combined = clip.ApplyNonRoundedIntersection(geometry->ComputeInvalidationRegion());
+          IntRect transformedRect = ToDeviceSpace(combined.GetBounds(), aMatrix, appUnitsPerDevPixel, mLayerBounds.TopLeft());
+          auto rect = transformedRect.Intersect(mImageBounds);
           GP("NoChange: %s %d %d %d %d\n", aItem->Name(),
                  aData->mRect.x, aData->mRect.y, aData->mRect.XMost(), aData->mRect.YMost());
+          MOZ_RELEASE_ASSERT(rect.IsEqualEdges(aData->mRect));
         }
       }
     }