Backport B+ tree implementation from Dart to Java.

editor/tools/plugins/com.google.dart.engine/src/com/google/dart/engine/internal/index/structure/btree/LeafNodeData.java

Index: editor/tools/plugins/com.google.dart.engine/src/com/google/dart/engine/internal/index/structure/btree/LeafNodeData.java
diff --git a/editor/tools/plugins/com.google.dart.server/src/com/google/dart/server/internal/remote/LineReaderStream.java b/editor/tools/plugins/com.google.dart.engine/src/com/google/dart/engine/internal/index/structure/btree/LeafNodeData.java
similarity index 62%
copy from editor/tools/plugins/com.google.dart.server/src/com/google/dart/server/internal/remote/LineReaderStream.java
copy to editor/tools/plugins/com.google.dart.engine/src/com/google/dart/engine/internal/index/structure/btree/LeafNodeData.java
index 62e425a9b8cbea8583078c7b5c81055a8c2112ce..436911acb695f89b6bbdcc243f429104f7cb2a74 100644
--- a/editor/tools/plugins/com.google.dart.server/src/com/google/dart/server/internal/remote/LineReaderStream.java
+++ b/editor/tools/plugins/com.google.dart.engine/src/com/google/dart/engine/internal/index/structure/btree/LeafNodeData.java
@@ -11,17 +11,21 @@
  * or implied. See the License for the specific language governing permissions and limitations under
  * the License.
  */
-package com.google.dart.server.internal.remote;
+package com.google.dart.engine.internal.index.structure.btree;
+
+import java.util.List;
 
 /**
- * A source of remote server lines.
+ * A container with information about a leaf node.
  * 
- * @coverage dart.server.remote
+ * @coverage dart.engine.index.structure
  */
-public interface LineReaderStream {
+public class LeafNodeData<K, V> {
+  public final List<K> keys;
+  public final List<V> values;
 
-  /**
-   * Takes the the next line from the stream and return it. Blocks if no response available.
-   */
-  String readLine() throws Exception;
+  public LeafNodeData(List<K> keys, List<V> values) {
+    this.keys = keys;
+    this.values = values;
+  }
 }