Apply gn format with 'sources' sorting to src/

sdch/BUILD.gn

Index: sdch/BUILD.gn
diff --git a/sdch/BUILD.gn b/sdch/BUILD.gn
index 70c778a01192be8aee078a001c1895daa775a0b8..3ceeeb47b054c9dd609819bf006889a8e0660bda 100644
--- a/sdch/BUILD.gn
+++ b/sdch/BUILD.gn
@@ -27,17 +27,17 @@ static_library("sdch") {
     "open-vcdiff/src/headerparser.h",
     "open-vcdiff/src/instruction_map.cc",
     "open-vcdiff/src/instruction_map.h",
-    "open-vcdiff/src/jsonwriter.h",
     "open-vcdiff/src/jsonwriter.cc",
+    "open-vcdiff/src/jsonwriter.h",
     "open-vcdiff/src/rolling_hash.h",
     "open-vcdiff/src/testing.h",
     "open-vcdiff/src/varint_bigendian.cc",
     "open-vcdiff/src/varint_bigendian.h",
     "open-vcdiff/src/vcdecoder.cc",
-    "open-vcdiff/src/vcencoder.cc",
     "open-vcdiff/src/vcdiff_defs.h",
     "open-vcdiff/src/vcdiffengine.cc",
     "open-vcdiff/src/vcdiffengine.h",
+    "open-vcdiff/src/vcencoder.cc",
     "open-vcdiff/vsprojects/config.h",
     "open-vcdiff/vsprojects/stdint.h",
   ]