Allow startup with missing V8 snapshot file.

content/browser/child_process_launcher.cc

Index: content/browser/child_process_launcher.cc
diff --git a/content/browser/child_process_launcher.cc b/content/browser/child_process_launcher.cc
index 28be72bb9c32eb853702adbdb0726379a3f9825c..5985a9e5ce5821a8d4803cc8cd43d9cc3e19d850 100644
--- a/content/browser/child_process_launcher.cc
+++ b/content/browser/child_process_launcher.cc
@@ -148,6 +148,8 @@ void LaunchOnLauncherThread(const NotifyCallback& callback,
   GetContentClient()->browser()->GetAdditionalMappedFilesForChildProcess(
       *cmd_line, child_process_id, files_to_register.get());
 
+  GetContentClient()->browser()->AppendMappedFileCommandLineSwitches(cmd_line);
+
   StartChildProcess(
       cmd_line->argv(), child_process_id, files_to_register.Pass(),
       base::Bind(&OnChildProcessStartedAndroid, callback, client_thread_id,
@@ -160,6 +162,9 @@ void LaunchOnLauncherThread(const NotifyCallback& callback,
 #if !defined(OS_MACOSX)
   GetContentClient()->browser()->GetAdditionalMappedFilesForChildProcess(
       *cmd_line, child_process_id, files_to_register.get());
+
+  GetContentClient()->browser()->AppendMappedFileCommandLineSwitches(cmd_line);

[rmcilroy, 2015/06/05 13:24:51]

nit - there is another call to GetAdditionalMappedFilesForChildProcess in
battery_monitor_integration_browsertest.cc - could you add the
AppendMappedFileCommandLineSwitches call there too please.

[Erik Corry Chromium.org, 2015/06/08 13:31:03]

In the end I didn't do this becasue the command line is const, and the call to
GetAdditionalMappedFilesForChildProcess is inside another implementation of
GetAdditionalMappedFilesForChildProcess, so the caller of the outer version can
be expected to call AppendMappedFileCommandLineSwitches

[rmcilroy, 2015/06/08 17:26:12]

Ahh well, if it works I guess this is fine.

+
   if (use_zygote) {
     base::ProcessHandle handle = ZygoteHostImpl::GetInstance()->ForkRequest(
         cmd_line->argv(), files_to_register.Pass(), process_type);