[cpu-profiler] Add a HandleScope to limit memory consumption.

The handles created for each SharedFunctionInfo within
SourcePosition::InliningStack live for the life of the profile,
reaching 5MiB+ on an example server application for Node.

This HandleScope limits their lifetime locally, given that the handles
do not escape.

This saves ~10% of peak memory.

Bug: v8:7719
Change-Id: I97ce0fd3658be89fdd9cb9c1369ea5bfae0ce579
Reviewed-on: https://chromium-review.googlesource.com/1049647Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Reviewed-by: Alexei Filippov <alph@chromium.org>
Commit-Queue: Peter Marshall <petermarshall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#53085}

src/profiler/profiler-listener.cc

@@ -17,7 +17,8 @@ namespace internal {
 
 ProfilerListener::ProfilerListener(Isolate* isolate,
                                    CodeEventObserver* observer)
-    : observer_(observer),
+    : isolate_(isolate),
+      observer_(observer),
       function_and_resource_names_(isolate->heap()->HashSeed()) {}
 
 ProfilerListener::~ProfilerListener() = default;
@@ -276,6 +277,11 @@ void ProfilerListener::RecordDeoptInlinedFrames(CodeEntry* entry,
       int deopt_id = static_cast<int>(info->data());
       DCHECK(last_position.IsKnown());
       std::vector<CpuProfileDeoptFrame> inlined_frames;
+
+      // SourcePosition::InliningStack allocates a handle for the SFI of each
+      // frame. These don't escape this function, but quickly add up. This
+      // scope limits their lifetime.
+      HandleScope scope(isolate_);
       for (SourcePositionInfo& pos_info : last_position.InliningStack(code)) {
         if (pos_info.position.ScriptOffset() == kNoSourcePosition) continue;
         if (!pos_info.function->script()->IsScript()) continue;

src/profiler/profiler-listener.h

@@ -84,6 +84,7 @@ class ProfilerListener : public CodeEventListener {
     observer_->CodeEventHandler(evt_rec);
   }
 
+  Isolate* isolate_;
   CodeEventObserver* observer_;
   StringsStorage function_and_resource_names_;
   std::deque<std::unique_ptr<CodeEntry>> code_entries_;