[inspector] fixed taskHeapSnapshot on pause

src/profiler/heap-snapshot-generator.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/profiler/heap-snapshot-generator.h"
 
 #include <utility>
 
 #include "src/code-stubs.h"
 #include "src/conversions.h"
@@ skipping 2474 matching lines @@
     v8::ActivityControl* control,
     v8::HeapProfiler::ObjectNameResolver* resolver,
     Heap* heap)
     : snapshot_(snapshot),
       control_(control),
       v8_heap_explorer_(snapshot_, this, resolver),
       dom_explorer_(snapshot_, this),
       heap_(heap) {
 }
 
+namespace {
+class NullContextScope {
+ public:
+  explicit NullContextScope(Isolate* isolate)
+      : isolate_(isolate), prev_(isolate->context()) {
+    isolate_->set_context(nullptr);
+  }
+  ~NullContextScope() { isolate_->set_context(prev_); }
+
+ private:
+  Isolate* isolate_;
+  Context* prev_;
+};
+}  //  namespace
 
 bool HeapSnapshotGenerator::GenerateSnapshot() {
   v8_heap_explorer_.TagGlobalObjects();
 
   // TODO(1562) Profiler assumes that any object that is in the heap after
   // full GC is reachable from the root when computing dominators.
   // This is not true for weakly reachable objects.
   // As a temporary solution we call GC twice.
   heap_->CollectAllGarbage(Heap::kMakeHeapIterableMask,
                            GarbageCollectionReason::kHeapProfiler);
   heap_->CollectAllGarbage(Heap::kMakeHeapIterableMask,
                            GarbageCollectionReason::kHeapProfiler);
 
+  NullContextScope null_context_scope(heap_->isolate());
+
 #ifdef VERIFY_HEAP
   Heap* debug_heap = heap_;
   if (FLAG_verify_heap) {
     debug_heap->Verify();
   }
 #endif
 
   SetProgressTotal(2);  // 2 passes.
 
 #ifdef VERIFY_HEAP
@@ skipping 597 matching lines @@
   for (int i = 1; i < sorted_strings.length(); ++i) {
     writer_->AddCharacter(',');
     SerializeString(sorted_strings[i]);
     if (writer_->aborted()) return;
   }
 }
 
 
 }  // namespace internal
 }  // namespace v8