Add source kind to the incremental cache.

pkg/analyzer/lib/src/summary/idl.dart

Index: pkg/analyzer/lib/src/summary/idl.dart
diff --git a/pkg/analyzer/lib/src/summary/idl.dart b/pkg/analyzer/lib/src/summary/idl.dart
index c99407004afe07d1d3ed6d4b35df7ac87e68e0af..f2d7a893d524e32ee2cc22001795a9f2c9f1de91 100644
--- a/pkg/analyzer/lib/src/summary/idl.dart
+++ b/pkg/analyzer/lib/src/summary/idl.dart
@@ -53,35 +53,46 @@ import 'format.dart' as generated;
 const informative = null;
 
 /**
- * Information about URIs referenced by a library.
+ * Information about a source that depends only on its content.
  */
-@TopLevel('CaLU')
-abstract class CacheLibraryUris extends base.SummaryClass {
-  factory CacheLibraryUris.fromBuffer(List<int> buffer) =>
-      generated.readCacheLibraryUris(buffer);
+@TopLevel('CaSS')
+abstract class CacheSourceContent extends base.SummaryClass {
+  factory CacheSourceContent.fromBuffer(List<int> buffer) =>
+      generated.readCacheSourceContent(buffer);
 
   /**
    * The list of exported URIs, e.g. `dart:core`, or `foo/bar.dart`,
    * or `package:foo/bar.dart`.

[Paul Berry, 2016/03/18 18:38:14]

Document what happens to this field when [kind] is CacheSourceKind.part.  (I
assume it's empty?)

[scheglov, 2016/03/18 19:42:06]

Done.

    */
-  @Id(1)
+  @Id(2)
   List<String> get exportedUris;
 
   /**
    * The list of explicitly imported URIs, e.g. `dart:core`, or `foo/bar.dart`,
    * or `package:foo/bar.dart`.

[Paul Berry, 2016/03/18 18:38:14]

Same here

[scheglov, 2016/03/18 19:42:06]

Done.

    */
-  @Id(0)
+  @Id(1)
   List<String> get importedUris;
 
   /**
+   * The kind of the source.
+   */
+  @Id(0)
+  CacheSourceKind get kind;
+
+  /**
    * The list of part URIs, e.g. `foo/bar.dart`.
    */
-  @Id(2)
+  @Id(3)
   List<String> get partUris;
 }
 
 /**
+ * Kind of a source in the cache.
+ */
+enum CacheSourceKind { library, part }
+
+/**
  * Information about an element code range.
  */
 abstract class CodeRange extends base.SummaryClass {