Replace getToolsRepository() with getToolsLabel(String labelValue) which prepends the tools repository path to the given string and parses the result as a label.

This is a cleaner way to access the tools repository label.

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MOS_MIGRATED_REVID=114105929
diff --git a/src/main/java/com/google/devtools/build/lib/analysis/RuleDefinitionEnvironment.java b/src/main/java/com/google/devtools/build/lib/analysis/RuleDefinitionEnvironment.java
index 2eab411..45200fb 100644
--- a/src/main/java/com/google/devtools/build/lib/analysis/RuleDefinitionEnvironment.java
+++ b/src/main/java/com/google/devtools/build/lib/analysis/RuleDefinitionEnvironment.java
@@ -28,7 +28,8 @@
   Label getLabel(String labelValue);
 
   /**
-   * Returns the path to the tools repository. It is different for blaze and bazel.
+   * Prepends the tools repository path to the given string and parses the result
+   * using {@link RuleDefinitionEnvironment#getLabel}
    */
-  String getToolsRepository();
+  Label getToolsLabel(String labelValue);
 }