Support piping log data over the service protocol

sdk/lib/developer/developer.dart

Index: sdk/lib/developer/developer.dart
diff --git a/sdk/lib/developer/developer.dart b/sdk/lib/developer/developer.dart
index 03c75c1fbb0c39eecdb3717ecdebb4f0bf94c035..04a3b0053516c8682c14e301ba517965451e970c 100644
--- a/sdk/lib/developer/developer.dart
+++ b/sdk/lib/developer/developer.dart
@@ -11,16 +11,17 @@
 ///
 library dart.developer;
 
+import 'dart:async';
 import 'dart:convert';
 
 part 'profiler.dart';
 
 /// If [when] is true, stop the program as if a breakpoint were hit at the
 /// following statement.
-/// 
+///
 /// Returns the value of [when]. Some debuggers may
 /// display [msg].
-/// 
+///
 /// NOTE: When invoked, the isolate will not return until a debugger
 /// continues execution. When running in the Dart VM the behaviour is the same
 /// regardless of whether or not a debugger is connected. When compiled to
@@ -29,6 +30,36 @@ part 'profiler.dart';
 external bool debugger({bool when: true, String msg});
 
 /// Send a reference to [object] to any attached debuggers.
-/// 
+///
 /// Debuggers may open an inspector on the object. Returns the argument.
 external inspect(object);
+
+/// Emit a log event.
+/// [sequenceNumber] is a monotonically increasing sequence number.

[rmacnak, 2015/07/17 00:17:56]

What happens if this is called with the same sequence number repeatedly? In
particular, independent event sources seem likely to choose conflicting sequence
numbers.

[Cutch, 2015/07/17 00:50:13]

Note that all of these fields and their restrictions are dictated by the logging
package.

With my UI right now, it makes no difference. In the future, we may sort log
items based on their sequence number. If a program can't keep their sequence
numbers straight they may have a problem. 

+/// [millisececondsSinceEpoch] is a timestamp.
+/// [level] is the severity level (value between 0 and 2000 inclusive).

[rmacnak, 2015/07/17 00:17:56]

Are high or low values more severe?

[Cutch, 2015/07/17 00:50:13]

Note that all of these fields and their restrictions are dictated by the logging
package.

High values are more severe.

+/// [name] is the name of the source of the log message.
+/// [message] is the log message.
+/// [zone] (optional) the zone where the log was emitted
+/// [error] (optional) an error object associated with this log event.
+/// [stackTrace] (optional) a stack trace associated with this log event.
+external log(int sequenceNumber,
+             int millisecondsSinceEpoch,
+             int level,
+             String name,
+             String message,
+             [Zone zone,
+              Object error,
+              StackTrace stackTrace]);
+
+/// Emit a log event for a a [LogRecord] from the [logging] package.
+void logOnRecord(dynamic logRecord) {
+  log(logRecord.sequenceNumber,
+      logRecord.time.millisecondsSinceEpoch,
+      logRecord.level.value,
+      logRecord.loggerName,
+      logRecord.message,
+      null,
+      logRecord.error,
+      logRecord.stackTrace);
+}