[core] Simplify asset:// implementation

* Move asset:// URL handling to DefaultFileSource.
* AssetFileSource implements FileSource interface and follows familiar implementation patterns.
* Move default implementation to platform/default, zip implementation to platform/android.
* Don't bother with modified / expires / etag -- assets are not cached so it doesn't matter.
* Don't bother with interleaving individual IO calls on the implementation thread. That adds a lot of complexity for very little benefit.

1 files changed, 0 insertions, 8 deletions

diff --git a/src/mbgl/util/url.cpp b/src/mbgl/util/url.cpp
index 1bd9f410fe..85d8bc5bd0 100644
--- a/src/mbgl/util/url.cpp
+++ b/src/mbgl/util/url.cpp
@@ -71,13 +71,5 @@ std::string templateTileURL(const std::string& url, const TileID& id, float pixe
     });
 }
 
-namespace {
-const std::string assetProtocol = "asset://";
-}
-
-bool isAssetURL(const std::string& url) {
-    return std::equal(assetProtocol.begin(), assetProtocol.end(), url.begin());
-}
-
 } // namespace util
 } // namespace mbgl