Consolidate GlobDescriptor functionality

Makes GlobDescriptor directly implement SkyKey and adds custom serialization
logic. This lets us narrow visibility and migrate yet another SkyKey away from
LegacySkyKey.

PiperOrigin-RevId: 180705483
diff --git a/src/test/java/com/google/devtools/build/lib/skyframe/BUILD b/src/test/java/com/google/devtools/build/lib/skyframe/BUILD
index a92f871..a4b01da 100644
--- a/src/test/java/com/google/devtools/build/lib/skyframe/BUILD
+++ b/src/test/java/com/google/devtools/build/lib/skyframe/BUILD
@@ -78,6 +78,7 @@
         "//src/main/java/com/google/devtools/build/lib/collect/nestedset",
         "//src/main/java/com/google/devtools/build/lib/concurrent",
         "//src/main/java/com/google/devtools/build/lib/rules/cpp",
+        "//src/main/java/com/google/devtools/build/lib/skyframe/serialization/testutils",
         "//src/main/java/com/google/devtools/build/lib/vfs",
         "//src/main/java/com/google/devtools/build/lib/vfs/inmemoryfs",
         "//src/main/java/com/google/devtools/build/skyframe",