Dev compiler debugger related tweaks.

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

Index: pkg/dev_compiler/lib/src/compiler/source_map_printer.dart
diff --git a/pkg/dev_compiler/lib/src/compiler/source_map_printer.dart b/pkg/dev_compiler/lib/src/compiler/source_map_printer.dart
index a17005964d5a09eb2c0d6d316229a648bf2d91c7..322138959091a10f851418cc8608cc8059b10d37 100644
--- a/pkg/dev_compiler/lib/src/compiler/source_map_printer.dart
+++ b/pkg/dev_compiler/lib/src/compiler/source_map_printer.dart
@@ -49,8 +49,14 @@ class SourceMapPrintingContext extends JS.SimpleJavaScriptPrintingContext {
       // parts.
       _currentTopLevelDeclaration = node;
       unit = node.getAncestor((n) => n is CompilationUnit);
+      var source = resolutionMap.elementDeclaredByCompilationUnit(unit).source;
+      // Use the uri for dart: uris instead of the path of the source file
+      // on disk as that results in much cleaner stack traces.
+      // Example:
+      // source.uri = dart:core/object.dart
+      // source.fullName = gen/patched_sdk/lib/core/object.dart
       sourcePath =
-          resolutionMap.elementDeclaredByCompilationUnit(unit).source.fullName;
+          source.isInSystemLibrary ? source.uri.toString() : source.fullName;
     }

[Jacob, 2017/04/15 02:26:49]

Jenny please review this change. This switches to showing dart: uris for all
system library files instead
of the confusing paths to their locations in the gen directory.

[Jennifer Messerly, 2017/04/17 21:37:05]

Nice!!!

     // Skip MethodDeclarations - in the case of a one line function it finds the
     // declaration rather than the body and confuses devtools.