Update from https://crrev.com/304121

gin/isolate_holder.cc

 // Copyright 2013 The Chromium 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 "gin/public/isolate_holder.h"
 
 #include <stdlib.h>
 #include <string.h>
 
+#include "base/files/memory_mapped_file.h"
 #include "base/logging.h"
 #include "base/message_loop/message_loop.h"
 #include "base/rand_util.h"
 #include "base/sys_info.h"
 #include "gin/array_buffer.h"
 #include "gin/debug_impl.h"
 #include "gin/function_template.h"
 #include "gin/per_isolate_data.h"
 #include "gin/public/v8_platform.h"
 #include "gin/run_microtasks_observer.h"
 
 #ifdef V8_USE_EXTERNAL_STARTUP_DATA
-#include "base/files/memory_mapped_file.h"
 #include "base/path_service.h"
 #endif  // V8_USE_EXTERNAL_STARTUP_DATA
 
 namespace gin {
 
 namespace {
 
 v8::ArrayBuffer::Allocator* g_array_buffer_allocator = NULL;
 
 bool GenerateEntropy(unsigned char* buffer, size_t amount) {
   base::RandBytes(buffer, amount);
   return true;
 }
 
-#ifdef V8_USE_EXTERNAL_STARTUP_DATA
 base::MemoryMappedFile* g_mapped_natives = NULL;
 base::MemoryMappedFile* g_mapped_snapshot = NULL;
 
+#ifdef V8_USE_EXTERNAL_STARTUP_DATA
 bool MapV8Files(base::FilePath* natives_path, base::FilePath* snapshot_path,
                 int natives_fd = -1, int snapshot_fd = -1) {
   int flags = base::File::FLAG_OPEN | base::File::FLAG_READ;
 
   g_mapped_natives = new base::MemoryMappedFile;
   if (!g_mapped_natives->IsValid()) {
     if (natives_fd == -1
         ? !g_mapped_natives->Initialize(base::File(*natives_path, flags))
         : !g_mapped_natives->Initialize(base::File(natives_fd))) {
       delete g_mapped_natives;
@@ skipping 22 matching lines @@
 }  // namespace
 
 
 #ifdef V8_USE_EXTERNAL_STARTUP_DATA
 // static
 bool IsolateHolder::LoadV8Snapshot() {
   if (g_mapped_natives && g_mapped_snapshot)
     return true;
 
   base::FilePath data_path;
-  PathService::Get(base::DIR_ANDROID_APP_DATA, &data_path);
+  PathService::Get(
+#if defined(OS_ANDROID)
+    base::DIR_ANDROID_APP_DATA,
+#elif defined(OS_POSIX)
+    base::DIR_EXE,
+#endif
+    &data_path);
   DCHECK(!data_path.empty());
 
   base::FilePath natives_path = data_path.AppendASCII("natives_blob.bin");
   base::FilePath snapshot_path = data_path.AppendASCII("snapshot_blob.bin");
 
   return MapV8Files(&natives_path, &snapshot_path);
 }
 
 //static
 bool IsolateHolder::LoadV8SnapshotFD(int natives_fd, int snapshot_fd) {
   if (g_mapped_natives && g_mapped_snapshot)
     return true;
 
   return MapV8Files(NULL, NULL, natives_fd, snapshot_fd);
 }
 #endif  // V8_USE_EXTERNAL_STARTUP_DATA
 
+//static
+void IsolateHolder::GetV8ExternalSnapshotData(const char** natives_data_out,
+                                              int* natives_size_out,
+                                              const char** snapshot_data_out,
+                                              int* snapshot_size_out) {
+  if (!g_mapped_natives || !g_mapped_snapshot) {
+    *natives_data_out = *snapshot_data_out = NULL;
+    *natives_size_out = *snapshot_size_out = 0;
+    return;
+  }
+  *natives_data_out = reinterpret_cast<const char*>(g_mapped_natives->data());
+  *snapshot_data_out = reinterpret_cast<const char*>(g_mapped_snapshot->data());
+  *natives_size_out = static_cast<int>(g_mapped_natives->length());
+  *snapshot_size_out = static_cast<int>(g_mapped_snapshot->length());
+}
+
 IsolateHolder::IsolateHolder() {
   CHECK(g_array_buffer_allocator)
       << "You need to invoke gin::IsolateHolder::Initialize first";
   v8::Isolate::CreateParams params;
   params.entry_hook = DebugImpl::GetFunctionEntryHook();
   params.code_event_handler = DebugImpl::GetJitCodeEventHandler();
   params.constraints.ConfigureDefaults(base::SysInfo::AmountOfPhysicalMemory(),
                                        base::SysInfo::AmountOfVirtualMemory(),
                                        base::SysInfo::NumberOfProcessors());
   isolate_ = v8::Isolate::New(params);
@@ skipping 40 matching lines @@
   v8::V8::SetArrayBufferAllocator(allocator);
   g_array_buffer_allocator = allocator;
   if (mode == gin::IsolateHolder::kStrictMode) {
     static const char v8_flags[] = "--use_strict";
     v8::V8::SetFlagsFromString(v8_flags, sizeof(v8_flags) - 1);
   }
   v8::V8::SetEntropySource(&GenerateEntropy);
 #ifdef V8_USE_EXTERNAL_STARTUP_DATA
   v8::StartupData natives;
   natives.data = reinterpret_cast<const char*>(g_mapped_natives->data());
-  natives.raw_size = g_mapped_natives->length();
-  natives.compressed_size = g_mapped_natives->length();
+  natives.raw_size = static_cast<int>(g_mapped_natives->length());
+  natives.compressed_size = static_cast<int>(g_mapped_natives->length());
   v8::V8::SetNativesDataBlob(&natives);
 
   v8::StartupData snapshot;
   snapshot.data = reinterpret_cast<const char*>(g_mapped_snapshot->data());
-  snapshot.raw_size = g_mapped_snapshot->length();
-  snapshot.compressed_size = g_mapped_snapshot->length();
+  snapshot.raw_size = static_cast<int>(g_mapped_snapshot->length());
+  snapshot.compressed_size = static_cast<int>(g_mapped_snapshot->length());
   v8::V8::SetSnapshotDataBlob(&snapshot);
 #endif  // V8_USE_EXTERNAL_STARTUP_DATA
   v8::V8::Initialize();
   v8_is_initialized = true;
 }
 
 void IsolateHolder::AddRunMicrotasksObserver() {
   DCHECK(!task_observer_.get());
   task_observer_.reset(new RunMicrotasksObserver(isolate_));;
   base::MessageLoop::current()->AddTaskObserver(task_observer_.get());
 }
 
 void IsolateHolder::RemoveRunMicrotasksObserver() {
   DCHECK(task_observer_.get());
   base::MessageLoop::current()->RemoveTaskObserver(task_observer_.get());
   task_observer_.reset();
 }
 
 }  // namespace gin