Rename some service protocol errors.

runtime/observatory/lib/src/elements/debugger.dart

Index: runtime/observatory/lib/src/elements/debugger.dart
diff --git a/runtime/observatory/lib/src/elements/debugger.dart b/runtime/observatory/lib/src/elements/debugger.dart
index e6db5f803af3514e2be7c6b5f089a6b461bdafdb..9fc8df5e06e53d5ca27e8376d1534d7858b5b41e 100644
--- a/runtime/observatory/lib/src/elements/debugger.dart
+++ b/runtime/observatory/lib/src/elements/debugger.dart
@@ -381,7 +381,7 @@ class BreakCommand extends DebuggerCommand {
         try {
           await debugger.isolate.addBreakpointAtEntry(loc.function);
         } on ServerRpcException catch(e) {
-          if (e.code == ServerRpcException.kNoBreakAtFunction) {
+          if (e.code == ServerRpcException.kCannotAddBreakpoint) {
             debugger.console.print('Unable to set breakpoint at ${loc}');
           } else {
             rethrow;
@@ -398,7 +398,7 @@ class BreakCommand extends DebuggerCommand {
         try {
           await debugger.isolate.addBreakpoint(loc.script, loc.line);
         } on ServerRpcException catch(e) {
-          if (e.code == ServerRpcException.kNoBreakAtLine) {
+          if (e.code == ServerRpcException.kCannotAddBreakpoint) {
             debugger.console.print('Unable to set breakpoint at ${loc}');
           } else {
             rethrow;