Add support to extension_shell and ash_shell to use external V8 snapshot files.

chrome/browser/chrome_content_browser_client.cc

 // Copyright (c) 2012 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 "chrome/browser/chrome_content_browser_client.h"
 
 #include <set>
 #include <utility>
 #include <vector>
 
@@ skipping 2391 matching lines @@
         browser_context, storage_partition_path, additional_backends);
   }
 }
 
 #if defined(OS_POSIX) && !defined(OS_MACOSX)
 void ChromeContentBrowserClient::GetAdditionalMappedFilesForChildProcess(
     const base::CommandLine& command_line,
     int child_process_id,
     FileDescriptorInfo* mappings) {
 #if defined(V8_USE_EXTERNAL_STARTUP_DATA)
-  if (v8_snapshot_fd_.get() == -1 && v8_natives_fd_.get() == -1) {
-    base::FilePath v8_data_path;
-    PathService::Get(gin::IsolateHolder::kV8SnapshotBasePathKey, &v8_data_path);
-    DCHECK(!v8_data_path.empty());
-
-    int file_flags = base::File::FLAG_OPEN | base::File::FLAG_READ;
-    base::FilePath v8_natives_data_path =
-        v8_data_path.AppendASCII(gin::IsolateHolder::kNativesFileName);
-    base::FilePath v8_snapshot_data_path =
-        v8_data_path.AppendASCII(gin::IsolateHolder::kSnapshotFileName);
-    base::File v8_natives_data_file(v8_natives_data_path, file_flags);
-    base::File v8_snapshot_data_file(v8_snapshot_data_path, file_flags);
-    DCHECK(v8_natives_data_file.IsValid());
-    DCHECK(v8_snapshot_data_file.IsValid());
-    v8_natives_fd_.reset(v8_natives_data_file.TakePlatformFile());
-    v8_snapshot_fd_.reset(v8_snapshot_data_file.TakePlatformFile());
+  if (v8_natives_fd_.get() == -1 || v8_snapshot_fd_.get() == -1) {
+    int v8_natives_fd = -1;
+    int v8_snapshot_fd = -1;
+    if (gin::IsolateHolder::OpenV8FilesForChildProcesses(&v8_natives_fd,
+                                                         &v8_snapshot_fd)) {
+      v8_natives_fd_.reset(v8_natives_fd);
+      v8_snapshot_fd_.reset(v8_snapshot_fd);
+    }
   }
+  DCHECK(v8_natives_fd_.get() != -1 && v8_snapshot_fd_.get() != -1);
   mappings->Share(kV8NativesDataDescriptor, v8_natives_fd_.get());
   mappings->Share(kV8SnapshotDataDescriptor, v8_snapshot_fd_.get());
 #endif  // V8_USE_EXTERNAL_STARTUP_DATA
 
 #if defined(OS_ANDROID)
   base::FilePath data_path;
   PathService::Get(ui::DIR_RESOURCE_PAKS_ANDROID, &data_path);
   DCHECK(!data_path.empty());
 
   int flags = base::File::FLAG_OPEN | base::File::FLAG_READ;
@@ skipping 201 matching lines @@
       switches::kDisableWebRtcEncryption,
     };
     to_command_line->CopySwitchesFrom(from_command_line,
                                       kWebRtcDevSwitchNames,
                                       arraysize(kWebRtcDevSwitchNames));
   }
 }
 #endif  // defined(ENABLE_WEBRTC)
 
 }  // namespace chrome