[snapshot] Add SnapshotDecompress RCS scope

We do have snapshot decompression trace events, let's also add a
runtime call stats scope for easy comparison.

Bug: chromium:1269494, chromium:1270039
Change-Id: If467cc38f37a0ea9d84e501b4984bf72736c8fa4
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3279962
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Auto-Submit: Camillo Bruni <cbruni@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/main@{#77898}

src/logging/runtime-call-stats.h

@@ -388,13 +388,13 @@ class RuntimeCallTimer final {
   V(BoundFunctionLengthGetter)                 \
   V(BoundFunctionNameGetter)                   \
   V(CodeGenerationFromStringsCallbacks)        \
+  V(CompileBackgroundBaselinePreVisit)         \
+  V(CompileBackgroundBaselineVisit)            \
   V(CompileBackgroundCompileTask)              \
   V(CompileBaseline)                           \
+  V(CompileBaselineFinalization)               \
   V(CompileBaselinePreVisit)                   \
   V(CompileBaselineVisit)                      \
-  V(CompileBackgroundBaselinePreVisit)         \
-  V(CompileBackgroundBaselineVisit)            \
-  V(CompileBaselineFinalization)               \
   V(CompileCollectSourcePositions)             \
   V(CompileDeserialize)                        \
   V(CompileEnqueueOnDispatcher)                \
@@ -469,6 +469,7 @@ class RuntimeCallTimer final {
   V(PrototypeMap_TransitionToDataProperty)     \
   V(PrototypeObject_DeleteProperty)            \
   V(ReconfigureToDataProperty)                 \
+  V(SnapshotDecompress)                        \
   V(StringLengthGetter)                        \
   V(TestCounter1)                              \
   V(TestCounter2)                              \
@@ -476,10 +477,10 @@ class RuntimeCallTimer final {
   V(UpdateProtector)                           \
   V(WebSnapshotDeserialize)                    \
   V(WebSnapshotDeserialize_Arrays)             \
+  V(WebSnapshotDeserialize_Classes)            \
   V(WebSnapshotDeserialize_Contexts)           \
   V(WebSnapshotDeserialize_Exports)            \
   V(WebSnapshotDeserialize_Functions)          \
-  V(WebSnapshotDeserialize_Classes)            \
   V(WebSnapshotDeserialize_Maps)               \
   V(WebSnapshotDeserialize_Objects)            \
   V(WebSnapshotDeserialize_Strings)

src/snapshot/snapshot.cc

@@ -120,9 +120,11 @@ class SnapshotImpl : public AllStatic {
 
 }  // namespace
 
-SnapshotData MaybeDecompress(const base::Vector<const byte>& snapshot_data) {
-  TRACE_EVENT0("v8", "V8.SnapshotDecompress");
+SnapshotData MaybeDecompress(Isolate* isolate,
+                             const base::Vector<const byte>& snapshot_data) {
 #ifdef V8_SNAPSHOT_COMPRESSION
+  TRACE_EVENT0("v8", "V8.SnapshotDecompress");
+  RCS_SCOPE(isolate, RuntimeCallCounterId::kSnapshotDecompress);
   return SnapshotCompression::Decompress(snapshot_data);
 #else
   return SnapshotData(snapshot_data);
@@ -182,9 +184,11 @@ bool Snapshot::Initialize(Isolate* isolate) {
     decompress_histogram.emplace(isolate->counters()->snapshot_decompress());
   }
 #endif
-  SnapshotData startup_snapshot_data(MaybeDecompress(startup_data));
-  SnapshotData read_only_snapshot_data(MaybeDecompress(read_only_data));
-  SnapshotData shared_heap_snapshot_data(MaybeDecompress(shared_heap_data));
+  SnapshotData startup_snapshot_data(MaybeDecompress(isolate, startup_data));
+  SnapshotData read_only_snapshot_data(
+      MaybeDecompress(isolate, read_only_data));
+  SnapshotData shared_heap_snapshot_data(
+      MaybeDecompress(isolate, shared_heap_data));
 #ifdef V8_SNAPSHOT_COMPRESSION
   decompress_histogram.reset();
 #endif
@@ -222,7 +226,7 @@ MaybeHandle<Context> Snapshot::NewContextFromSnapshot(
           isolate->counters()->context_snapshot_decompress());
     }
 #endif
-    snapshot_data.emplace(MaybeDecompress(context_data));
+    snapshot_data.emplace(MaybeDecompress(isolate, context_data));
   }
 
   MaybeHandle<Context> maybe_result = ContextDeserializer::DeserializeContext(