Plumb through memory allocation profiler feature to Chrome Inspector

Summary: Changelog: Make allocation profiler feature of Chome Inspector work

Reviewed By: dulinriley

Differential Revision: D20383003

fbshipit-source-id: 8a10c310d5a639a6644763adb53f2f0017057587

API/hermes/hermes.cpp

@@ -490,6 +490,16 @@ class HermesRuntimeImpl final : public HermesRuntime,
     runtime_.getHeap().collect();
   }
 
+  // Overridden from jsi::Instrumentation
+  void startTrackingHeapObjectStackTraces() override {
+    runtime_.enableAllocationLocationTracker();
+  }
+
+  // Overridden from jsi::Instrumentation
+  void stopTrackingHeapObjectStackTraces() override {
+    runtime_.disableAllocationLocationTracker();
+  }
+
   // Overridden from jsi::Instrumentation
   void createSnapshotToFile(const std::string &path) override {
     std::error_code code;
@@ -932,7 +942,7 @@ class HermesRuntimeImpl final : public HermesRuntime,
   template <typename T>
   struct ManagedValues {
 #ifdef ASSERT_ON_DANGLING_VM_REFS
-    // If we have active HermesValuePointers whhen deconstructing, these will
+    // If we have active HermesValuePointers when deconstructing, these will
     // now be dangling. We deliberately allocate and immediately leak heap
     // memory to hold the internal list. This keeps alive memory holding the
     // ref-count of the now dangling references, allowing them to detect the

API/jsi/jsi/decorator.h

@@ -335,6 +335,14 @@ class RuntimeDecorator : public Base, private jsi::Instrumentation {
     plain().instrumentation().collectGarbage();
   }
 
+  void startTrackingHeapObjectStackTraces() override {
+    plain().instrumentation().startTrackingHeapObjectStackTraces();
+  }
+
+  void stopTrackingHeapObjectStackTraces() override {
+    plain().instrumentation().stopTrackingHeapObjectStackTraces();
+  }
+
   void createSnapshotToFile(const std::string& path) override {
     plain().instrumentation().createSnapshotToFile(path);
   }

API/jsi/jsi/instrumentation.h

@@ -52,6 +52,13 @@ class Instrumentation {
   /// perform a full garbage collection
   virtual void collectGarbage() = 0;
 
+  /// Start capturing JS stack-traces for all JS heap allocated objects. These
+  /// can be accessed via \c ::createSnapshotToFile().
+  virtual void startTrackingHeapObjectStackTraces() = 0;
+
+  /// Stop capture JS stack-traces for JS heap allocated objects.
+  virtual void stopTrackingHeapObjectStackTraces() = 0;
+
   /// Captures the heap to a file
   ///
   /// \param path to save the heap capture

API/jsi/jsi/jsi.cpp

@@ -99,6 +99,9 @@ Instrumentation& Runtime::instrumentation() {
 
     void collectGarbage() override {}
 
+    void startTrackingHeapObjectStackTraces() override {}
+    void stopTrackingHeapObjectStackTraces() override {}
+
     void createSnapshotToFile(const std::string&) override {
       throw JSINativeException(
           "Default instrumentation cannot create a heap snapshot");