Refactor AttributeInfo into a proto

This is a no-op in functionality, but begins to pave the way for a proto output format for Stardoc.

RELNOTES: None.
PiperOrigin-RevId: 244020123
diff --git a/src/test/java/com/google/devtools/build/skydoc/BUILD b/src/test/java/com/google/devtools/build/skydoc/BUILD
index bcfc620..cff1161 100644
--- a/src/test/java/com/google/devtools/build/skydoc/BUILD
+++ b/src/test/java/com/google/devtools/build/skydoc/BUILD
@@ -28,6 +28,7 @@
         "//src/main/java/com/google/devtools/build/skydoc:skydoc_lib",
         "//src/main/java/com/google/devtools/build/skydoc/fakebuildapi",
         "//src/main/java/com/google/devtools/build/skydoc/rendering",
+        "//src/main/java/com/google/devtools/build/skydoc/rendering/proto:stardoc_output_java_proto",
         "//src/test/java/com/google/devtools/build/lib:testutil",
         "//src/test/java/com/google/devtools/build/lib/skylark:testutil",
         "//third_party:guava",
diff --git a/src/test/java/com/google/devtools/build/skydoc/SkydocTest.java b/src/test/java/com/google/devtools/build/skydoc/SkydocTest.java
index 4b5c3b0..0601cf6 100644
--- a/src/test/java/com/google/devtools/build/skydoc/SkydocTest.java
+++ b/src/test/java/com/google/devtools/build/skydoc/SkydocTest.java
@@ -28,10 +28,10 @@
 import com.google.devtools.build.lib.vfs.FileSystemUtils;
 import com.google.devtools.build.lib.vfs.Path;
 import com.google.devtools.build.skydoc.SkydocMain.StarlarkEvaluationException;
-import com.google.devtools.build.skydoc.rendering.AttributeInfo;
 import com.google.devtools.build.skydoc.rendering.RuleInfo;
 import com.google.devtools.build.skydoc.rendering.UserDefinedFunctionInfo;
 import com.google.devtools.build.skydoc.rendering.UserDefinedFunctionInfo.DocstringParseException;
+import com.google.devtools.build.skydoc.rendering.proto.StardocOutputProtos.AttributeType;
 import java.io.IOException;
 import java.util.Map;
 import java.util.Map.Entry;
@@ -130,12 +130,14 @@
     assertThat(ruleInfo.getValue().getDocString()).isEqualTo("This is my rule. It does stuff.");
     assertThat(getAttrNames(ruleInfo.getValue())).containsExactly(
         "name", "a", "b", "c", "d").inOrder();
-    assertThat(getAttrTypes(ruleInfo.getValue())).containsExactly(
-        AttributeInfo.Type.NAME,
-        AttributeInfo.Type.LABEL,
-        AttributeInfo.Type.STRING_DICT,
-        AttributeInfo.Type.OUTPUT,
-        AttributeInfo.Type.BOOLEAN).inOrder();
+    assertThat(getAttrTypes(ruleInfo.getValue()))
+        .containsExactly(
+            AttributeType.NAME,
+            AttributeType.LABEL,
+            AttributeType.STRING_DICT,
+            AttributeType.OUTPUT,
+            AttributeType.BOOLEAN)
+        .inOrder();
   }
 
   private static Iterable<String> getAttrNames(RuleInfo ruleInfo) {
@@ -143,7 +145,7 @@
         .collect(Collectors.toList());
   }
 
-  private static Iterable<AttributeInfo.Type> getAttrTypes(RuleInfo ruleInfo) {
+  private static Iterable<AttributeType> getAttrTypes(RuleInfo ruleInfo) {
     return ruleInfo.getAttributes().stream().map(attr -> attr.getType())
         .collect(Collectors.toList());
   }