Make default media device ID salts random by default

content/shell/browser/shell_browser_context.cc

Index: content/shell/browser/shell_browser_context.cc
diff --git a/content/shell/browser/shell_browser_context.cc b/content/shell/browser/shell_browser_context.cc
index aad4a0eb338910407c752efeada2a597c66550a3..51d3f201be608d22ef98cb3ef297a552fc000b7e 100644
--- a/content/shell/browser/shell_browser_context.cc
+++ b/content/shell/browser/shell_browser_context.cc
@@ -33,8 +33,7 @@
 namespace content {
 
 ShellBrowserContext::ShellResourceContext::ShellResourceContext()
-    : getter_(NULL) {
-}
+    : getter_(NULL), media_device_id_salt_(CreateRandomMediaDeviceIDSalt()) {}
 
 ShellBrowserContext::ShellResourceContext::~ShellResourceContext() {
 }
@@ -51,6 +50,11 @@ ShellBrowserContext::ShellResourceContext::GetRequestContext() {
   return getter_->GetURLRequestContext();
 }
 
+ResourceContext::SaltCallback
+ShellBrowserContext::ShellResourceContext::GetMediaDeviceIDSalt() {
+  return CreateSaltCallback(media_device_id_salt_);
+}
+
 ShellBrowserContext::ShellBrowserContext(bool off_the_record,
                                          net::NetLog* net_log)
     : resource_context_(new ShellResourceContext),