Big merge from experimental to bleeding edge.

sdk/lib/core/string_buffer.dart

Index: sdk/lib/core/string_buffer.dart
diff --git a/sdk/lib/core/string_buffer.dart b/sdk/lib/core/string_buffer.dart
index fda711180b87694cca9e8c48621ecef622115e4f..71bf31d2a0066e8590d2d7f8182061be9a2a367a 100644
--- a/sdk/lib/core/string_buffer.dart
+++ b/sdk/lib/core/string_buffer.dart
@@ -27,7 +27,7 @@ abstract class StringBuffer {
   void addCharCode(int charCode);
 
   /// Adds all items in [objects] to the buffer.
-  void addAll(Collection objects);
+  void addAll(Iterable objects);
 
   /// Clears the string buffer.
   void clear();
@@ -66,7 +66,7 @@ class _StringBufferImpl implements StringBuffer {
   }
 
   /// Adds all items in [objects] to the buffer.
-  void addAll(Collection objects) {
+  void addAll(Iterable objects) {
     for (Object obj in objects) add(obj);
   }