Remove backends.

compiler/javatests/com/google/dart/compiler/CompilerTestCase.java

Index: compiler/javatests/com/google/dart/compiler/CompilerTestCase.java
diff --git a/compiler/javatests/com/google/dart/compiler/CompilerTestCase.java b/compiler/javatests/com/google/dart/compiler/CompilerTestCase.java
index e6f949dc8f838ed10bc6b552fd8d96d3b82883cd..2affb905cfa35a580383bd5e3e0d00d633f45d1f 100644
--- a/compiler/javatests/com/google/dart/compiler/CompilerTestCase.java
+++ b/compiler/javatests/com/google/dart/compiler/CompilerTestCase.java
@@ -45,11 +45,6 @@ public abstract class CompilerTestCase extends TestCase {
   protected static final CompilerConfiguration CHECK_ONLY_CONFIGURATION =
       new DefaultCompilerConfiguration(new CompilerOptions()) {
         @Override
-        public boolean checkOnly() {
-          return true;
-        }
-
-        @Override
         public boolean incremental() {
           return true;
         }
@@ -211,14 +206,14 @@ public abstract class CompilerTestCase extends TestCase {
   }
 
   /**
-   * Compiles a single unit with a synthesized application, using the specified backend.
+   * Compiles a single unit with a synthesized application.
    */
   protected DartSource compileSingleUnit(String name, String code,
-       DartArtifactProvider provider, Backend backend) throws IOException {
+       DartArtifactProvider provider) throws IOException {
      MockLibrarySource lib = new MockLibrarySource();
      DartSourceTest src = new DartSourceTest(name, code, lib);
      lib.addSource(src);
-     CompilerConfiguration config = getCompilerConfiguration(backend);
+     CompilerConfiguration config = getCompilerConfiguration();
      DartCompilerListener listener = new DartCompilerListenerTest(src.getName());
      DartCompiler.compileLib(lib, config, provider, listener);
      return src;
@@ -227,8 +222,8 @@ public abstract class CompilerTestCase extends TestCase {
   /**
    * Allow tests to override the configuration used.
    */
-  protected CompilerConfiguration getCompilerConfiguration(Backend backend) {
-    return new DefaultCompilerConfiguration(backend);
+  protected CompilerConfiguration getCompilerConfiguration() {
+    return new DefaultCompilerConfiguration();
   }
 
   /**