Merge "SF: Interleave writes to HWC with other work"

    const bool updatingGeometryThisFrame = mGeometryInvalid;

    mGeometryInvalid = false;

    {

        // Use a map so that we latch the state of each front-end layer once.

        std::unordered_map<compositionengine::LayerFE*, compositionengine::LayerFECompositionState*>

                uniqueVisibleLayers;

        // Figure out which frontend layers are being composed, and build the unique

        // set of them (and the corresponding composition layer)

    // Latch the frontend layer composition state for each layer being

    // composed.

    for (const auto& [token, displayDevice] : mDisplays) {

        auto display = displayDevice->getCompositionDisplay();

        for (auto& layer : display->getOutputLayersOrderedByZ()) {

                uniqueVisibleLayers.insert(std::make_pair(&layer->getLayerFE(),

                                                          &layer->getLayer().editState().frontEnd));

            }

        }

        // Update the composition state from each front-end layer.

        for (auto& [layerFE, state] : uniqueVisibleLayers) {

            layerFE->latchCompositionState(*state, updatingGeometryThisFrame);

            layer->getLayerFE().latchCompositionState(layer->getLayer().editState().frontEnd,

                                                      updatingGeometryThisFrame);

        }

    }

            // Update the composition state of the output layer, as needed

            // recomputing it from the state given by the front-end layer.

            layer->updateCompositionState(updatingGeometryThisFrame);

        }

    }

    for (const auto& [token, displayDevice] : mDisplays) {

        auto display = displayDevice->getCompositionDisplay();

        for (auto& layer : display->getOutputLayersOrderedByZ()) {

            // Send the updated state to the HWC, if appropriate.

            layer->writeStateToHWC(updatingGeometryThisFrame);

        }