Inline source maps as part of each script.

pkg/dev_compiler/lib/src/compiler/code_generator.dart

Index: pkg/dev_compiler/lib/src/compiler/code_generator.dart
diff --git a/pkg/dev_compiler/lib/src/compiler/code_generator.dart b/pkg/dev_compiler/lib/src/compiler/code_generator.dart
index 59633e63f52c5b6e986e85488147712cd18604d8..0b134d6610f01dad7788020bb7e59d567f497bc2 100644
--- a/pkg/dev_compiler/lib/src/compiler/code_generator.dart
+++ b/pkg/dev_compiler/lib/src/compiler/code_generator.dart
@@ -322,7 +322,8 @@ class CodeGenerator extends GeneralizingAstVisitor
 
     // Track the module name for each library in the module.
     // This data is only required for debugging.
-    _moduleItems.add(js.statement('#.trackLibraries(#, #);',
+    _moduleItems.add(js.statement(
+        '#.trackLibraries(#, #, ${JSModuleFile.sourceMapHoleID});',
         [_runtimeModule, js.string(name), _librariesDebuggerObject()]));
 
     // Add the module's code (produced by visiting compilation units, above)