Fix some service protocol typos.

runtime/vm/service/service.md

 # Dart VM Service Protocol 3.0
 
 > Please post feedback to the [observatory-discuss group][discuss-list]
 
 This document describes of _version 3.0_ 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,
@@ skipping 449 matching lines @@
                                    string targetId,
                                    string expression)
 ```
 
 The _evaluate_ RPC is used to evaluate an expression in the context of
 some target.
 
 _targetId_ may refer to a [Library](#library), [Class](#class), or
 [Instance](#instance).
 
-If _targetId_ is a temporary id which has expired, then then _Expired_
+If _targetId_ is a temporary id which has expired, then the _Expired_
 [Sentinel](#sentinel) is returned.
 
 If _targetId_ refers to an object which has been collected by the VM's
 garbage collector, then the _Collected_ [Sentinel](#sentinel) is
 returned.
 
 If an error occurs while evaluating the expression, an [@Error](#error)
 reference will be returned.
 
 If the expression is evaluated successfully, an [@Instance](#instance)
@@ skipping 47 matching lines @@
 ```
 Object|Sentinel getObject(string isolateId,
                           string objectId,
                           int offset [optional],
                           int count [optional])
 ```
 
 The _getObject_ RPC is used to lookup an _object_ from some isolate by
 its _id_.
 
-If _objectId_ is a temporary id which has expired, then then _Expired_
+If _objectId_ is a temporary id which has expired, then the _Expired_
 [Sentinel](#sentinel) is returned.
 
 If _objectId_ refers to a heap object which has been collected by the VM's
 garbage collector, then the _Collected_ [Sentinel](#sentinel) is
 returned.
 
 If _objectId_ refers to a non-heap object which has been deleted, then
 the _Collected_ [Sentinel](#sentinel) is returned.
 
 If the object handle has not expired and the object has not been
@@ skipping 765 matching lines @@
 }
 ```
 
 ### Function
 
 ```
 class @Function extends @Object {
   // The name of this function.
   string name;
 
-  // The owner of this field, which can be a Library, Class, or a
-  // Function.
+  // The owner of this function, which can be a Library, Class, or a Function.
   @Library|@Class|@Function owner;
 
   // Is this function static?
   bool static;
 
   // Is this function const?
   bool const;
 }
 ```
 
 An _@Function_ is a reference to a _Function_.
 
 
 ```
 class Function extends Object {
   // The name of this function.
   string name;
 
-  // The owner of this field, which can be a Library, Class, or a
-  // Function.
+  // The owner of this function, which can be a Library, Class, or a Function.
   @Library|@Class|@Function owner;
 
   // The location of this function in the source code.
   SourceLocation location [optional];
 
   // The compiled code associated with this function.
   @Code code [optional];
 }
 ```
 
@@ skipping 333 matching lines @@
 
   // An instance of the built-in VM Map implementation. User-defined
   // Maps will be PlainInstance.
   Map,
 
   // Vector instance kinds.
   Float32x4,
   Float64x2,
   Int32x4
 
-  // An instance of the built-in VM TypedData implementations.  User-defined
+  // An instance of the built-in VM TypedData implementations. User-defined
   // TypedDatas will be PlainInstance.
   Uint8ClampedList,
   Uint8List,
   Uint16List,
   Uint32List,
   Uint64List,
   Int8List,
   Int16List,
   Int32List,
   Int64List,
@@ skipping 12 matching lines @@
 
   // An instance of the Dart class MirrorReference.
   MirrorReference,
 
   // An instance of the Dart class RegExp.
   RegExp,
 
   // An instance of the Dart class WeakProperty.
   WeakProperty,
 
-  // An instance of the Dart class Type
+  // An instance of the Dart class Type.
   Type,
 
-  // An instance of the Dart class TypeParamer
+  // An instance of the Dart class TypeParameter.
   TypeParameter,
 
-  // An instance of the Dart class TypeRef
+  // An instance of the Dart class TypeRef.
   TypeRef,
 
-  // An instance of the Dart class BoundedType
+  // An instance of the Dart class BoundedType.
   BoundedType,
 }
 ```
 
 Adding new values to _InstanceKind_ is considered a backwards
 compatible change. Clients should treat unrecognized instance kinds
 as _PlainInstance_.
 
 ### Isolate
 
@@ skipping 74 matching lines @@
 _@Library_ is a reference to a _Library_.
 
 ```
 class Library extends Object {
   // The name of this library.
   string name;
 
   // The uri of this library.
   string uri;
 
-  // Is this library debuggable?  Default true.
+  // Is this library debuggable? Default true.
   bool debuggable;
 
   // A list of the imports for this library.
   LibraryDependency[] dependencies;
 
   // A list of the scripts which constitute this library.
   @Script[] scripts;
 
   // A list of the top-level variables in this library.
   @Field[] variables;
@@ skipping 332 matching lines @@
 
 ```
 class UnresolvedSourceLocation extends Response {
   // The script containing the source location if the script has been loaded.
   @Script script [optional];
 
   // The uri of the script containing the source location if the script
   // has yet to be loaded.
   string scriptUri [optional];
 
-  // An approximate token position for the source location.  This may
+  // An approximate token position for the source location. This may
   // change when the location is resolved.
   int tokenPos [optional];
 
-  // An approximate line number for the source location.  This may
+  // An approximate line number for the source location. This may
   // change when the location is resolved.
   int line [optional];
 
-  // An approximate column number for the source location.  This may
+  // An approximate column number for the source location. This may
   // change when the location is resolved.
   int column [optional];
 
 }
 ```
 
 The _UnresolvedSourceLocation_ class is used to refer to an unresolved
 breakpoint location.  As such, it is meant to approximate the final
 location of the breakpoint but it is not exact.
 
@@ skipping 61 matching lines @@
 ## Revision History
 
 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.
 
 
 [discuss-list]: https://groups.google.com/a/dartlang.org/forum/#!forum/observatory-discuss