[core] Refactor RenderSource updates

* Eliminate updateBatch in favor of diffing layers and detecting changes to properties upon which layout depends.
* Replace RenderSource::{update,remove,invalidate,reload}Tiles with a single update method
* Replace TilePyramid::{update,remove,invalidate,reload}Tiles with a single update method
* Remove Style& dependency TODO from GeometryTile and TileParameters

src/mbgl/renderer/render_source.cpp

@@ -3,6 +3,7 @@
 #include <mbgl/renderer/sources/render_geojson_source.hpp>
 #include <mbgl/renderer/sources/render_raster_source.hpp>
 #include <mbgl/renderer/sources/render_vector_source.hpp>
+#include <mbgl/renderer/tile_parameters.hpp>
 #include <mbgl/annotation/render_annotation_source.hpp>
 #include <mbgl/renderer/sources/render_image_source.hpp>
 #include <mbgl/tile/tile.hpp>
@@ -44,10 +45,6 @@ void RenderSource::setObserver(RenderSourceObserver* observer_) {
     observer = observer_;
 }
 
-void RenderSource::setImpl(Immutable<style::Source::Impl> impl) {
-    baseImpl = impl;
-}
-
 void RenderSource::onTileChanged(Tile& tile) {
     observer->onTileChanged(*this, tile.id);
 }
@@ -56,4 +53,8 @@ void RenderSource::onTileError(Tile& tile, std::exception_ptr error) {
     observer->onTileError(*this, tile.id, error);
 }
 
+bool RenderSource::isEnabled() const {
+    return enabled;
+}
+
 } // namespace mbgl