Extract DiagnosticReporter implementation from Compiler.

pkg/compiler/lib/src/mirrors/dart2js_mirrors.dart

Index: pkg/compiler/lib/src/mirrors/dart2js_mirrors.dart
diff --git a/pkg/compiler/lib/src/mirrors/dart2js_mirrors.dart b/pkg/compiler/lib/src/mirrors/dart2js_mirrors.dart
index 287afb98c8b3a57e8bdb92ebc99e829621ac515f..247e3f5244b91efe6eab228e4d3c736f73e0cc10 100644
--- a/pkg/compiler/lib/src/mirrors/dart2js_mirrors.dart
+++ b/pkg/compiler/lib/src/mirrors/dart2js_mirrors.dart
@@ -135,7 +135,7 @@ abstract class Dart2JsDeclarationMirror extends Dart2JsMirror
       }
       return members;
     }
-    mirrorSystem.compiler.internalError(element,
+    mirrorSystem.compiler.reporter.internalError(element,
         "Unexpected member type $element ${element.kind}.");
     return null;
   }
@@ -208,8 +208,8 @@ abstract class Dart2JsElementMirror extends Dart2JsDeclarationMirror {
       span = new SourceSpan(script.resourceUri, 0, 0);
     } else {
       Token endToken = getEndToken();
-      span = mirrorSystem.compiler.spanFromTokens(
-          beginToken, endToken, script.resourceUri);
+      span = new SourceSpan.fromTokens(
+          script.resourceUri, beginToken, endToken);
     }
     return new Dart2JsSourceLocation(script, span);
   }
@@ -348,7 +348,7 @@ class Dart2JsMirrorSystem extends MirrorSystem {
         return new Dart2JsTypedefMirror(this, type);
       }
     }
-    compiler.internalError(type.element,
+    compiler.reporter.internalError(type.element,
         "Unexpected type $type of kind ${type.kind}.");
     return null;
   }
@@ -359,7 +359,7 @@ class Dart2JsMirrorSystem extends MirrorSystem {
     } else if (element.isTypedef) {
       return new Dart2JsTypedefDeclarationMirror(this, element.thisType);
     }
-    compiler.internalError(element, "Unexpected element $element.");
+    compiler.reporter.internalError(element, "Unexpected element $element.");
     return null;
   }
 }