Use command line to signal whether a child process was passed V8 snapshot files via file descriptor

content/shell/browser/shell_content_browser_client.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 "content/shell/browser/shell_content_browser_client.h"
 
 #include "base/base_switches.h"
 #include "base/command_line.h"
 #include "base/files/file.h"
 #include "base/files/file_util.h"
@@ skipping 191 matching lines @@
   for (size_t i = 0; i < arraysize(kProtocolList); ++i) {
     if (url.scheme() == kProtocolList[i])
       return true;
   }
   return false;
 }
 
 void ShellContentBrowserClient::AppendExtraCommandLineSwitches(
     base::CommandLine* command_line,
     int child_process_id) {
+#if defined(OS_POSIX) && !defined(OS_MACOSX)
+#if defined(V8_USE_EXTERNAL_STARTUP_DATA)
+  std::string process_type =
+      command_line->GetSwitchValueASCII(switches::kProcessType);
+  if (process_type != switches::kZygoteProcess) {
+    command_line->AppendSwitch(::switches::kV8NativesPassedByFD);
+    command_line->AppendSwitch(::switches::kV8SnapshotPassedByFD);
+  }
+#endif  // V8_USE_EXTERNAL_STARTUP_DATA
+#endif  // OS_POSIX && !OS_MACOSX
   if (base::CommandLine::ForCurrentProcess()->HasSwitch(
           switches::kRunLayoutTest))
     command_line->AppendSwitch(switches::kRunLayoutTest);
   if (base::CommandLine::ForCurrentProcess()->HasSwitch(
           switches::kEnableFontAntialiasing))
     command_line->AppendSwitch(switches::kEnableFontAntialiasing);
   if (base::CommandLine::ForCurrentProcess()->HasSwitch(
           switches::kExposeInternalsForTesting))
     command_line->AppendSwitch(switches::kExposeInternalsForTesting);
   if (base::CommandLine::ForCurrentProcess()->HasSwitch(
@@ skipping 193 matching lines @@
 ShellBrowserContext*
 ShellContentBrowserClient::ShellBrowserContextForBrowserContext(
     BrowserContext* content_browser_context) {
   if (content_browser_context == browser_context())
     return browser_context();
   DCHECK_EQ(content_browser_context, off_the_record_browser_context());
   return off_the_record_browser_context();
 }
 
 }  // namespace content