fix TileLayer clear when spatialReference changed, and fix specs

Author: fuzhenn

src/layer/tile/TileLayer.js

@@ -753,6 +753,9 @@ class TileLayer extends Layer {
         if (this._renderer) {
             this._renderer.clear();
         }
+        if (this.tileInfoCache) {
+            this.tileInfoCache.reset();
+        }
         /**
          * clear event, fired when tile layer is cleared.
          *
@@ -1282,6 +1285,10 @@ class TileLayer extends Layer {
         delete this._sr;
         delete this._srMinZoom;
         delete this._hasOwnSR;
+        delete this._rootNodes;
+        if (this.tileInfoCache) {
+            this.tileInfoCache.reset();
+        }
         const renderer = this.getRenderer();
         if (renderer) {
             renderer.clear();

test/map/spatial-reference/SpatialRefUpdateSpec.js

@@ -44,15 +44,15 @@ describe('SpatialReference.Update', function () {
             });
             var tiles = tileLayer.getTiles().tileGrids[0].tiles;
             var tile = tiles[tiles.length - 1];
-            expect(tile.extent2d.xmin).to.be.eql(-256);
-            expect(tile.extent2d.ymax).to.be.eql(0);
+            expect(tile.x).to.be.eql(-1);
+            expect(tile.y).to.be.eql(0);
             done();
         });
         map.setBaseLayer(tileLayer);
         var tiles = tileLayer.getTiles().tileGrids[0].tiles;
         var tile = tiles[tiles.length - 1];
-        expect(tile.extent2d.xmin).to.be.eql(-256);
-        expect(tile.extent2d.ymax).to.be.eql(256);
+        expect(tile.x).to.be.eql(8191);
+        expect(tile.y).to.be.eql(8191);
     });
 
     var geometries = GEN_GEOMETRIES_OF_ALL_TYPES();