Do not record CPU profile samples when stack collection is failed.

BUG=559304
LOG=N

Review URL: https://codereview.chromium.org/1709873002

Cr-Commit-Position: refs/heads/master@{#34168}

src/profiler/profile-generator.cc

@@ -360,7 +360,7 @@ void CpuProfile::AddPath(base::TimeTicks timestamp,
                          bool update_stats) {
   ProfileNode* top_frame_node =
       top_down_.AddPathFromEnd(path, src_line, update_stats);
-  if (record_samples_) {
+  if (record_samples_ && !timestamp.IsNull()) {
     timestamps_.Add(timestamp);
     samples_.Add(top_frame_node);
   }
@@ -636,10 +636,9 @@ void ProfileGenerator::RecordTickSample(const TickSample& sample) {
       }
     }
 
-    for (const Address* stack_pos = sample.stack,
-           *stack_end = stack_pos + sample.frames_count;
-         stack_pos != stack_end;
-         ++stack_pos) {
+    for (const Address *stack_pos = sample.stack,
+                       *stack_end = stack_pos + sample.frames_count;
+         stack_pos != stack_end; ++stack_pos) {
       *entry = code_map_.FindEntry(*stack_pos);
 
       // Skip unresolved frames (e.g. internal frame) and get source line of

src/profiler/sampler.cc

@@ -671,6 +671,8 @@ DISABLE_ASAN void TickSample::Init(Isolate* isolate,
   if (js_entry_sp == 0) return;  // Not executing JS now.
 
   if (pc && IsNoFrameRegion(pc)) {
+    // Can't collect stack. Mark the sample as spoiled.
+    timestamp = base::TimeTicks();
     pc = 0;
     return;
   }
@@ -701,6 +703,12 @@ DISABLE_ASAN void TickSample::Init(Isolate* isolate,
   GetStackSample(isolate, regs, record_c_entry_frame,
                  reinterpret_cast<void**>(&stack[0]), kMaxFramesCount, &info);
   frames_count = static_cast<unsigned>(info.frames_count);
+  if (!frames_count) {
+    // It is executing JS but failed to collect a stack trace.
+    // Mark the sample as spoiled.
+    timestamp = base::TimeTicks();
+    pc = 0;
+  }
 }
 
 
@@ -797,7 +805,7 @@ void Sampler::SampleStack(const v8::RegisterState& state) {
   TickSample sample_obj;
   if (sample == NULL) sample = &sample_obj;
   sample->Init(isolate_, state, TickSample::kIncludeCEntryFrame, true);
-  if (is_counting_samples_) {
+  if (is_counting_samples_ && !sample->timestamp.IsNull()) {
     if (sample->state == JS) ++js_sample_count_;
     if (sample->state == EXTERNAL) ++external_sample_count_;
   }

test/cctest/test-profile-generator.cc

@@ -428,11 +428,13 @@ TEST(SampleIds) {
   // (root)#1 -> aaa #2 -> bbb #4 -> ccc #5 - sample2
   //                    -> ccc #6 -> aaa #7 - sample3
   TickSample sample1;
+  sample1.timestamp = v8::base::TimeTicks::HighResolutionNow();
   sample1.pc = ToAddress(0x1600);
   sample1.stack[0] = ToAddress(0x1510);
   sample1.frames_count = 1;
   generator.RecordTickSample(sample1);
   TickSample sample2;
+  sample2.timestamp = v8::base::TimeTicks::HighResolutionNow();
   sample2.pc = ToAddress(0x1925);
   sample2.stack[0] = ToAddress(0x1780);
   sample2.stack[1] = ToAddress(0x10000);  // non-existent.
@@ -440,6 +442,7 @@ TEST(SampleIds) {
   sample2.frames_count = 3;
   generator.RecordTickSample(sample2);
   TickSample sample3;
+  sample3.timestamp = v8::base::TimeTicks::HighResolutionNow();
   sample3.pc = ToAddress(0x1510);
   sample3.stack[0] = ToAddress(0x1910);
   sample3.stack[1] = ToAddress(0x1610);