diff --git a/test/inspector/BUILD.gn b/test/inspector/BUILD.gn
index 5298c09a89..9c9774719e 100644
--- a/test/inspector/BUILD.gn
+++ b/test/inspector/BUILD.gn
@@ -11,6 +11,8 @@ v8_executable("inspector-test") {
     "inspector-impl.cc",
     "inspector-impl.h",
     "inspector-test.cc",
+    "isolate-data.cc",
+    "isolate-data.h",
     "task-runner.cc",
     "task-runner.h",
   ]
diff --git a/test/inspector/inspector.gyp b/test/inspector/inspector.gyp
index a5bdf64e09..26f44d4812 100644
--- a/test/inspector/inspector.gyp
+++ b/test/inspector/inspector.gyp
@@ -23,6 +23,8 @@
         'inspector-impl.cc',
         'inspector-impl.h',
         'inspector-test.cc',
+        'isolate-data.cc',
+        'isolate-data.h',
         'task-runner.cc',
         'task-runner.h',
       ],
diff --git a/test/inspector/isolate-data.cc b/test/inspector/isolate-data.cc
new file mode 100644
index 0000000000..06ba710b3e
--- /dev/null
+++ b/test/inspector/isolate-data.cc
@@ -0,0 +1,79 @@
+// Copyright 2017 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 "test/inspector/isolate-data.h"
+
+#include "test/inspector/inspector-impl.h"
+#include "test/inspector/task-runner.h"
+
+namespace {
+
+const int kIsolateDataIndex = 2;
+
+v8::internal::Vector<uint16_t> ToVector(v8::Local<v8::String> str) {
+  v8::internal::Vector<uint16_t> buffer =
+      v8::internal::Vector<uint16_t>::New(str->Length());
+  str->Write(buffer.start(), 0, str->Length());
+  return buffer;
+}
+
+}  //  namespace
+
+IsolateData::IsolateData(TaskRunner* task_runner,
+                         IsolateData::SetupGlobalTasks setup_global_tasks,
+                         v8::StartupData* startup_data)
+    : task_runner_(task_runner),
+      setup_global_tasks_(std::move(setup_global_tasks)) {
+  v8::Isolate::CreateParams params;
+  params.array_buffer_allocator =
+      v8::ArrayBuffer::Allocator::NewDefaultAllocator();
+  params.snapshot_blob = startup_data;
+  isolate_ = v8::Isolate::New(params);
+  isolate_->SetMicrotasksPolicy(v8::MicrotasksPolicy::kScoped);
+}
+
+IsolateData* IsolateData::FromContext(v8::Local<v8::Context> context) {
+  return static_cast<IsolateData*>(
+      context->GetAlignedPointerFromEmbedderData(kIsolateDataIndex));
+}
+
+int IsolateData::CreateContextGroup() {
+  v8::Local<v8::ObjectTemplate> global_template =
+      v8::ObjectTemplate::New(isolate_);
+  for (auto it = setup_global_tasks_.begin(); it != setup_global_tasks_.end();
+       ++it) {
+    (*it)->Run(isolate_, global_template);
+  }
+  v8::Local<v8::Context> context =
+      v8::Context::New(isolate_, nullptr, global_template);
+  context->SetAlignedPointerInEmbedderData(kIsolateDataIndex, this);
+  int context_group_id = ++last_context_group_id_;
+  contexts_[context_group_id].Reset(isolate_, context);
+  return context_group_id;
+}
+
+v8::Local<v8::Context> IsolateData::GetContext(int context_group_id) {
+  return contexts_[context_group_id].Get(isolate_);
+}
+
+void IsolateData::RegisterModule(v8::Local<v8::Context> context,
+                                 v8::internal::Vector<uint16_t> name,
+                                 v8::ScriptCompiler::Source* source) {
+  v8::Local<v8::Module> module;
+  if (!v8::ScriptCompiler::CompileModule(isolate(), source).ToLocal(&module))
+    return;
+  if (!module->Instantiate(context, &IsolateData::ModuleResolveCallback))
+    return;
+  v8::Local<v8::Value> result;
+  if (!module->Evaluate(context).ToLocal(&result)) return;
+  modules_[name] = v8::Global<v8::Module>(isolate_, module);
+}
+
+v8::MaybeLocal<v8::Module> IsolateData::ModuleResolveCallback(
+    v8::Local<v8::Context> context, v8::Local<v8::String> specifier,
+    v8::Local<v8::Module> referrer) {
+  std::string str = *v8::String::Utf8Value(specifier);
+  IsolateData* data = IsolateData::FromContext(context);
+  return data->modules_[ToVector(specifier)].Get(data->isolate_);
+}
diff --git a/test/inspector/isolate-data.h b/test/inspector/isolate-data.h
new file mode 100644
index 0000000000..8a5555d051
--- /dev/null
+++ b/test/inspector/isolate-data.h
@@ -0,0 +1,62 @@
+// Copyright 2017 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.
+
+#ifndef V8_TEST_INSPECTOR_PROTOCOL_ISOLATE_DATA_H_
+#define V8_TEST_INSPECTOR_PROTOCOL_ISOLATE_DATA_H_
+
+#include <map>
+
+#include "include/v8-inspector.h"
+#include "include/v8-platform.h"
+#include "include/v8.h"
+#include "src/vector.h"
+
+class TaskRunner;
+
+class IsolateData {
+ public:
+  class SetupGlobalTask {
+   public:
+    virtual ~SetupGlobalTask() = default;
+    virtual void Run(v8::Isolate* isolate,
+                     v8::Local<v8::ObjectTemplate> global) = 0;
+  };
+  using SetupGlobalTasks = std::vector<std::unique_ptr<SetupGlobalTask>>;
+
+  IsolateData(TaskRunner* task_runner, SetupGlobalTasks setup_global_tasks,
+              v8::StartupData* startup_data);
+  static IsolateData* FromContext(v8::Local<v8::Context> context);
+
+  v8::Isolate* isolate() const { return isolate_; }
+  TaskRunner* task_runner() const { return task_runner_; }
+  int CreateContextGroup();
+  v8::Local<v8::Context> GetContext(int context_group_id);
+  void RegisterModule(v8::Local<v8::Context> context,
+                      v8::internal::Vector<uint16_t> name,
+                      v8::ScriptCompiler::Source* source);
+
+ private:
+  struct VectorCompare {
+    bool operator()(const v8::internal::Vector<uint16_t>& lhs,
+                    const v8::internal::Vector<uint16_t>& rhs) const {
+      for (int i = 0; i < lhs.length() && i < rhs.length(); ++i) {
+        if (lhs[i] != rhs[i]) return lhs[i] < rhs[i];
+      }
+      return false;
+    }
+  };
+  static v8::MaybeLocal<v8::Module> ModuleResolveCallback(
+      v8::Local<v8::Context> context, v8::Local<v8::String> specifier,
+      v8::Local<v8::Module> referrer);
+
+  TaskRunner* task_runner_;
+  SetupGlobalTasks setup_global_tasks_;
+  v8::Isolate* isolate_;
+  int last_context_group_id_ = 0;
+  std::map<int, v8::Global<v8::Context>> contexts_;
+  std::map<v8::internal::Vector<uint16_t>, v8::Global<v8::Module>,
+           VectorCompare>
+      modules_;
+};
+#endif  //  V8_TEST_INSPECTOR_PROTOCOL_ISOLATE_DATA_H_
diff --git a/test/inspector/task-runner.cc b/test/inspector/task-runner.cc
index 5f21b9cab2..b26680fdf6 100644
--- a/test/inspector/task-runner.cc
+++ b/test/inspector/task-runner.cc
@@ -12,8 +12,6 @@
 
 namespace {
 
-const int kIsolateDataIndex = 2;
-
 void ReportUncaughtException(v8::Isolate* isolate,
                              const v8::TryCatch& try_catch) {
   CHECK(try_catch.HasCaught());
@@ -31,64 +29,6 @@ v8::internal::Vector<uint16_t> ToVector(v8::Local<v8::String> str) {
 
 }  //  namespace
 
-IsolateData::IsolateData(TaskRunner* task_runner,
-                         IsolateData::SetupGlobalTasks setup_global_tasks,
-                         v8::StartupData* startup_data)
-    : task_runner_(task_runner),
-      setup_global_tasks_(std::move(setup_global_tasks)) {
-  v8::Isolate::CreateParams params;
-  params.array_buffer_allocator =
-      v8::ArrayBuffer::Allocator::NewDefaultAllocator();
-  params.snapshot_blob = startup_data;
-  isolate_ = v8::Isolate::New(params);
-  isolate_->SetMicrotasksPolicy(v8::MicrotasksPolicy::kScoped);
-}
-
-IsolateData* IsolateData::FromContext(v8::Local<v8::Context> context) {
-  return static_cast<IsolateData*>(
-      context->GetAlignedPointerFromEmbedderData(kIsolateDataIndex));
-}
-
-int IsolateData::CreateContextGroup() {
-  v8::Local<v8::ObjectTemplate> global_template =
-      v8::ObjectTemplate::New(isolate_);
-  for (auto it = setup_global_tasks_.begin(); it != setup_global_tasks_.end();
-       ++it) {
-    (*it)->Run(isolate_, global_template);
-  }
-  v8::Local<v8::Context> context =
-      v8::Context::New(isolate_, nullptr, global_template);
-  context->SetAlignedPointerInEmbedderData(kIsolateDataIndex, this);
-  int context_group_id = ++last_context_group_id_;
-  contexts_[context_group_id].Reset(isolate_, context);
-  return context_group_id;
-}
-
-v8::Local<v8::Context> IsolateData::GetContext(int context_group_id) {
-  return contexts_[context_group_id].Get(isolate_);
-}
-
-void IsolateData::RegisterModule(v8::Local<v8::Context> context,
-                                 v8::internal::Vector<uint16_t> name,
-                                 v8::ScriptCompiler::Source* source) {
-  v8::Local<v8::Module> module;
-  if (!v8::ScriptCompiler::CompileModule(isolate(), source).ToLocal(&module))
-    return;
-  if (!module->Instantiate(context, &IsolateData::ModuleResolveCallback))
-    return;
-  v8::Local<v8::Value> result;
-  if (!module->Evaluate(context).ToLocal(&result)) return;
-  modules_[name] = v8::Global<v8::Module>(isolate_, module);
-}
-
-v8::MaybeLocal<v8::Module> IsolateData::ModuleResolveCallback(
-    v8::Local<v8::Context> context, v8::Local<v8::String> specifier,
-    v8::Local<v8::Module> referrer) {
-  std::string str = *v8::String::Utf8Value(specifier);
-  IsolateData* data = IsolateData::FromContext(context);
-  return data->modules_[ToVector(specifier)].Get(data->isolate_);
-}
-
 TaskRunner::TaskRunner(IsolateData::SetupGlobalTasks setup_global_tasks,
                        bool catch_exceptions,
                        v8::base::Semaphore* ready_semaphore,
diff --git a/test/inspector/task-runner.h b/test/inspector/task-runner.h
index db94d8bd1a..2052c621d1 100644
--- a/test/inspector/task-runner.h
+++ b/test/inspector/task-runner.h
@@ -15,54 +15,7 @@
 #include "src/base/platform/platform.h"
 #include "src/locked-queue-inl.h"
 #include "src/vector.h"
-
-class TaskRunner;
-
-class IsolateData {
- public:
-  class SetupGlobalTask {
-   public:
-    virtual ~SetupGlobalTask() = default;
-    virtual void Run(v8::Isolate* isolate,
-                     v8::Local<v8::ObjectTemplate> global) = 0;
-  };
-  using SetupGlobalTasks = std::vector<std::unique_ptr<SetupGlobalTask>>;
-
-  IsolateData(TaskRunner* task_runner, SetupGlobalTasks setup_global_tasks,
-              v8::StartupData* startup_data);
-  static IsolateData* FromContext(v8::Local<v8::Context> context);
-
-  v8::Isolate* isolate() const { return isolate_; }
-  TaskRunner* task_runner() const { return task_runner_; }
-  int CreateContextGroup();
-  v8::Local<v8::Context> GetContext(int context_group_id);
-  void RegisterModule(v8::Local<v8::Context> context,
-                      v8::internal::Vector<uint16_t> name,
-                      v8::ScriptCompiler::Source* source);
-
- private:
-  struct VectorCompare {
-    bool operator()(const v8::internal::Vector<uint16_t>& lhs,
-                    const v8::internal::Vector<uint16_t>& rhs) const {
-      for (int i = 0; i < lhs.length() && i < rhs.length(); ++i) {
-        if (lhs[i] != rhs[i]) return lhs[i] < rhs[i];
-      }
-      return false;
-    }
-  };
-  static v8::MaybeLocal<v8::Module> ModuleResolveCallback(
-      v8::Local<v8::Context> context, v8::Local<v8::String> specifier,
-      v8::Local<v8::Module> referrer);
-
-  TaskRunner* task_runner_;
-  SetupGlobalTasks setup_global_tasks_;
-  v8::Isolate* isolate_;
-  int last_context_group_id_ = 0;
-  std::map<int, v8::Global<v8::Context>> contexts_;
-  std::map<v8::internal::Vector<uint16_t>, v8::Global<v8::Module>,
-           VectorCompare>
-      modules_;
-};
+#include "test/inspector/isolate-data.h"
 
 class TaskRunner : public v8::base::Thread {
  public: