[core] Synchronize render passes and render tiles

Before this change render passes were assigned for the
whole layer at properties evaluation stage.

This caused problems, as layer render data are bound
to the tile and these data might differ from tile to
tile, depending on which tile has been updated by the
tile worker and which has not been yet updated.

This change takes into consideration the actual render
passes required for each tile and combines them for
the layer render passes. Naturally, this change also
introduces render pass check for each render layer in
`RenderLayer::render()` implementations.

src/mbgl/renderer/render_layer.cpp

@@ -48,7 +48,7 @@ bool RenderLayer::supportsZoom(float zoom) const {
 void RenderLayer::prepare(const LayerPrepareParameters& params) {
     assert(params.source);
     renderTiles = params.source->getRenderTiles();
-    assert(renderTiles);
+    addRenderPassesFromTiles();
 }
 
 optional<Color> RenderLayer::getSolidBackground() const {
@@ -86,5 +86,21 @@ void RenderLayer::checkRenderability(const PaintParameters& parameters,
     }
 }
 
+void RenderLayer::addRenderPassesFromTiles() {
+    assert(renderTiles);
+    for (const RenderTile& tile : *renderTiles) {
+        if (const LayerRenderData* renderData = tile.getLayerRenderData(*baseImpl)) {
+            passes |= RenderPass(renderData->layerProperties->renderPasses);
+        }
+    }
+}
+
+const LayerRenderData* RenderLayer::getRenderDataForPass(const RenderTile& tile, RenderPass pass) const {
+    if (const LayerRenderData* renderData = tile.getLayerRenderData(*baseImpl)) {
+        return bool(RenderPass(renderData->layerProperties->renderPasses) & pass) ? renderData : nullptr;
+    }
+    return nullptr;
+}
+
 } //namespace mbgl