Add "color" support to WebGL image replay

This adds support for layer brightness, contrast, hue, saturation.

src/ol/renderer/webgl/webglmaprenderer.js

@@ -291,9 +291,14 @@ ol.renderer.webgl.Map.prototype.dispatchComposeEvent_ =
       var center = viewState.center;
       var rotation = viewState.rotation;
       var size = frameState.size;
+      // use default color values
       var opacity = 1;
+      var brightness = 0;
+      var contrast = 1;
+      var hue = 0;
+      var saturation = 1;
       replayGroup.replay(context, center, resolution, rotation, size, extent,
-          pixelRatio, opacity, {});
+          pixelRatio, opacity, brightness, contrast, hue, saturation, {});
     }
     this.replayGroup = replayGroup;
   }

src/ol/renderer/webgl/webglvectorlayerrenderer.js

@@ -73,8 +73,8 @@ ol.renderer.webgl.VectorLayer.prototype.composeFrame =
     replayGroup.replay(context,
         viewState.center, viewState.resolution, viewState.rotation,
         frameState.size, frameState.extent, frameState.pixelRatio,
-        layerState.opacity,
-        frameState.skippedFeatureUids);
+        layerState.opacity, layerState.brightness, layerState.contrast,
+        layerState.hue, layerState.saturation, frameState.skippedFeatureUids);
   }
 
 };