Allow startup with missing V8 snapshot file.

chromecast/browser/cast_content_browser_client.h

Index: chromecast/browser/cast_content_browser_client.h
diff --git a/chromecast/browser/cast_content_browser_client.h b/chromecast/browser/cast_content_browser_client.h
index 5e5c262f92a103087e4856b5e9ec9a72bf0bc45f..ca27a8657a94111dad0639064f099c18d4162036 100644
--- a/chromecast/browser/cast_content_browser_client.h
+++ b/chromecast/browser/cast_content_browser_client.h
@@ -60,6 +60,8 @@ class CastContentBrowserClient: public content::ContentBrowserClient {
   bool IsHandledURL(const GURL& url) override;
   void AppendExtraCommandLineSwitches(base::CommandLine* command_line,
                                       int child_process_id) override;
+  void AppendMappedFileCommandLineSwitches(
+      base::CommandLine* command_line) override;
   content::AccessTokenStore* CreateAccessTokenStore() override;
   void OverrideWebkitPrefs(content::RenderViewHost* render_view_host,
                            content::WebPreferences* prefs) override;
@@ -131,6 +133,8 @@ class CastContentBrowserClient: public content::ContentBrowserClient {
 
   base::ScopedFD v8_natives_fd_;
   base::ScopedFD v8_snapshot_fd_;
+  bool natives_fd_exists() { return v8_natives_fd_ != -1; }
+  bool snapshot_fd_exists() { return v8_snapshot_fd_ != -1; }
 
   scoped_ptr<URLRequestContextFactory> url_request_context_factory_;