allow simple

BUG=skia:

Review URL: https://codereview.chromium.org/824753006

tools/PictureRenderingFlags.cpp

@@ -139,6 +139,7 @@ sk_tools::PictureRenderer* parseRenderer(SkString& error, PictureTool tool) {
 #endif
         } else if (0 == strcmp(mode, "rerecord") && kRender_PictureTool == tool) {
             renderer.reset(SkNEW_ARGS(sk_tools::RecordPictureRenderer, RENDERER_ARGS));
+        } else if (0 == strcmp(mode, "simple")) {
             // Allow 'mode' to be set to 'simple', but do not create a renderer, so we can
             // ensure that pipe does not override a mode besides simple. The renderer will
             // be created below.