Initialize the bootstrap sandbox in the browser process.

content/public/common/sandbox_type_mac.h

Index: content/public/common/sandbox_type_mac.h
diff --git a/content/public/common/sandbox_type_mac.h b/content/public/common/sandbox_type_mac.h
index b034ba51dc2aa4c3cb68c67ea2ba41a29397c9a4..4121ae4db9b93bda9ae7614a0b04d683b5a100cb 100644
--- a/content/public/common/sandbox_type_mac.h
+++ b/content/public/common/sandbox_type_mac.h
@@ -11,6 +11,9 @@ namespace content {
 // additional sandbox types with IDs starting with SANDBOX_TYPE_AFTER_LAST_TYPE.
 
 enum SandboxType {
+  // Not a valid sandbox type.
+  SANDBOX_TYPE_INVALID = -1,
+
   SANDBOX_TYPE_FIRST_TYPE = 0,  // Placeholder to ease iteration.
 
   SANDBOX_TYPE_RENDERER = SANDBOX_TYPE_FIRST_TYPE,
@@ -31,6 +34,10 @@ enum SandboxType {
   // The PPAPI plugin process.
   SANDBOX_TYPE_PPAPI,
 
+  // The NPAPI plugin process. This does not use a Seatbelt/.sb sandbox policy,
+  // but it uses a bootstrap sandbox.
+  SANDBOX_TYPE_NPAPI,
+
   SANDBOX_TYPE_AFTER_LAST_TYPE,  // Placeholder to ease iteration.
 };