Add getCallSiteData to the VM service.

runtime/vm/service/service.idl

 //
 // TODO(turnidge): Finish writing an idl description of the service protocol.
 //
 
 interface Service {
   getVM() VM
 
   getFlagList() FlagList
 
   setFlag(name string, value string) Response
@@ skipping 28 matching lines @@
   // Evaluate an expression in the context of some target.
   eval(isolateId string, targetId string, expression string) InstanceRef
 
   // Returns the current execution stack for an isolate.
   getStack(isolateId string) Stack
 
   // Returns code coverage information for a library, script, class,
   // or function.
   getCoverage(isolateId string, targetId string) CodeCoverage
 
+  // Returns call site cache information for a function.
+  getCallSiteData(isolateId string, targetId string) _CallSiteData
+
   // Returns a full cpu profile for an isolate.
   //
   // <code>tagSelector</code> is optional with default 'UserVM'.
   getCpuProfile(isolateId string, tags TagSelector) CpuProfile
 
 
   // Returns a simple tag-based profile for an isolate.
   getTagProfile(isolateId string) TagProfile
 
   // Returns an allocation profile for an isolate.
@@ skipping 207 matching lines @@
 // A <code>Stack</code> represents an isolate's execution stack.
 struct Stack extends Response {
   frames []Frame
 }
 
 
 struct CodeCoverage extends Response {
   placeholder int
 }
 
+
+struct _CacheEntry {
+  receiverClass ClassRef
+  count         int
+}
+
+
+struct _CallSite {
+  name         string
+  line         int
+  column       int
+  cacheEntries []_CacheEntry
+}
+
+
+struct _CallSiteData extends Response {
+  function  FunctionRef
+  callSites []_CallSite
+}
+
 // A <code>TagProfile</code> is a limited profile encoded as parallel
 // arrays of tag names and tag values.
 struct TagProfile extends Response {
   names    []string
   counters []int
 }
 
 
 // A list of <code>Breakpoint</code>
 struct BreakpointList extends Response {
@@ skipping 123 matching lines @@
   VMOnly
   None
 }
 
 // A <code>MetricSelector</code> is used to indicate which list of metrics
 // should be retrieved from an isolate.
 enum MetricSelector {
   Dart,
   Native,
 }