Fix getSourceReport's forceCompile option for unused classes.

runtime/vm/service/service.md

-# Dart VM Service Protocol 3.4
+# Dart VM Service Protocol 3.5
 
 > Please post feedback to the [observatory-discuss group][discuss-list]
 
-This document describes of _version 3.4_ of the Dart VM Service Protocol. This
+This document describes of _version 3.5_ of the Dart VM Service Protocol. This
 protocol is used to communicate with a running Dart Virtual Machine.
 
 To use the Service Protocol, start the VM with the *--observe* flag.
 The VM will start a webserver which services protocol requests via WebSocket.
 It is possible to make HTTP (non-WebSocket) requests,
 but this does not allow access to VM _events_ and is not documented
 here.
 
 The Service Protocol uses [JSON-RPC 2.0][].
 
@@ skipping 97 matching lines @@
 was successful, the _result_ property provides the result.
 
 Here is an example response for our [getVersion](#getversion) request above:
 
 ```
 {
   "jsonrpc": "2.0",
   "result": {
     "type": "Version",
     "major": 3,
-    "minor": 0
+    "minor": 5
   }
   "id": "1"
 }
 ```
 
 Parameters for RPC requests are always provided as _named_ parameters.
 The JSON-RPC spec provides for _positional_ parameters as well, but they
 are not supported by the Dart VM.
 
 By convention, every response returned by the Service Protocol is a subtype
@@ skipping 170 matching lines @@
 ## Versioning
 
 The [getVersion](#getversion) RPC can be used to find the version of the protocol
 returned by a VM. The _Version_ response has a major and a minor
 version number:
 
 ```
   "result": {
     "type": "Version",
     "major": 3,
-    "minor": 0
+    "minor": 5
   }
 ```
 
 The major version number is incremented when the protocol is changed
 in a potentially _incompatible_ way. An example of an incompatible
 change is removing a non-optional property from a result.
 
 The minor version number is incremented when the protocol is changed
 in a _backwards compatible_ way. An example of a backwards compatible
 change is adding a property to a result.
@@ skipping 1985 matching lines @@
 
   // The token position at which this range begins.
   int startPos;
 
   // The token position at which this range ends.  Inclusive.
   int endPos;
 
   // Has this range been compiled by the Dart VM?
   bool compiled;
 
+  // The error while attempting to compile this range, if this
+  // report was generated with forceCompile=true.
+  @Error error [optional];
+
   // Code coverage information for this range.  Provided only when the
   // Coverage report has been requested and the range has been
   // compiled.
   SourceReportCoverage coverage [optional];
 
   // Possible breakpoint information for this range, represented as a
   // sorted list of token positions.  Provided only when the when the
   // PossibleBreakpoint report has been requested and the range has been
   // compiled.
   int[] possibleBreakpoints [optional];
@@ skipping 182 matching lines @@
 
 version | comments
 ------- | --------
 1.0 | initial revision
 2.0 | Describe protocol version 2.0.
 3.0 | Describe protocol version 3.0.  Added UnresolvedSourceLocation.  Added Sentinel return to getIsolate.  Add AddedBreakpointWithScriptUri.  Removed Isolate.entry. The type of VM.pid was changed from string to int.  Added VMUpdate events.  Add offset and count parameters to getObject() and offset and count fields to Instance. Added ServiceExtensionAdded event.
 3.1 | Add the getSourceReport RPC.  The getObject RPC now accepts offset and count for string objects.  String objects now contain length, offset, and count properties.
 3.2 | Isolate objects now include the runnable bit and many debugger related RPCs will return an error if executed on an isolate before it is runnable.
 3.3 | Pause event now indicates if the isolate is paused at an await, yield, or yield* suspension point via the 'atAsyncSuspension' field. Resume command now supports the step parameter 'OverAsyncSuspension'. A Breakpoint added synthetically by an 'OverAsyncSuspension' resume command identifies itself as such via the 'isSyntheticAsyncContinuation' field.
 3.4 | Add the superType and mixin fields to Class. Added new pause event 'None'.
+3.5 | Add the error field to SourceReportRange.
 [discuss-list]: https://groups.google.com/a/dartlang.org/forum/#!forum/observatory-discuss