Remember thread's task when sampling use it when filtering

runtime/vm/profiler.h

Index: runtime/vm/profiler.h
diff --git a/runtime/vm/profiler.h b/runtime/vm/profiler.h
index 450e5da3f6e22c89d2580fcf631b5d12bb4fab25..1f65c917a8961dce73d3a9b49dbf7d3f87f879db 100644
--- a/runtime/vm/profiler.h
+++ b/runtime/vm/profiler.h
@@ -91,11 +91,14 @@ class SampleVisitor : public ValueObject {
 class SampleFilter : public ValueObject {
  public:
   SampleFilter(Isolate* isolate,
+               intptr_t thread_task_mask,
                int64_t time_origin_micros,
                int64_t time_extent_micros)
       : isolate_(isolate),
+        thread_task_mask_(thread_task_mask),
         time_origin_micros_(time_origin_micros),
         time_extent_micros_(time_extent_micros) {
+    ASSERT(thread_task_mask != 0);
     ASSERT(time_origin_micros_ >= -1);
     ASSERT(time_extent_micros_ >= -1);
   }
@@ -114,9 +117,12 @@ class SampleFilter : public ValueObject {
   // Returns |true| if |sample| passes the time filter.
   bool TimeFilterSample(Sample* sample);
 
+  // Returns |true| if |sample| passes the thread task filter.
+  bool TaskFilterSample(Sample* sample);
+
  private:
   Isolate* isolate_;
-
+  intptr_t thread_task_mask_;
   int64_t time_origin_micros_;
   int64_t time_extent_micros_;
 };
@@ -274,12 +280,12 @@ class Sample {
     state_ = ClassAllocationSampleBit::update(allocation_sample, state_);
   }
 
-  bool is_mutator_thread() const {
-    return MutatorThreadBit::decode(state_);
+  Thread::TaskKind thread_task() const {
+    return ThreadTaskBit::decode(state_);
   }
 
-  void set_is_mutator_thread(bool mutator_thread) {
-    state_ = MutatorThreadBit::update(mutator_thread, state_);
+  void set_thread_task(Thread::TaskKind task) {
+    state_ = ThreadTaskBit::update(task, state_);
   }
 
   bool is_continuation_sample() const {
@@ -346,7 +352,8 @@ class Sample {
     kTruncatedTraceBit = 5,
     kClassAllocationSampleBit = 6,
     kContinuationSampleBit = 7,
-    kMutatorThreadBit = 8,
+    kThreadTaskBit = 8,  // 4 bits.
+    kNextFreeBit = 12,
   };
   class HeadSampleBit : public BitField<uword, bool, kHeadSampleBit, 1> {};
   class LeafFrameIsDart :
@@ -361,8 +368,8 @@ class Sample {
       : public BitField<uword, bool, kClassAllocationSampleBit, 1> {};
   class ContinuationSampleBit
       : public BitField<uword, bool, kContinuationSampleBit, 1> {};
-  class MutatorThreadBit
-      : public BitField<uword, bool, kMutatorThreadBit, 1> {};
+  class ThreadTaskBit
+      : public BitField<uword, Thread::TaskKind, kThreadTaskBit, 4> {};
 
   int64_t timestamp_;
   ThreadId tid_;