Chromecast: disables application cache.

Chromecast application cache is disabled due to storage constraints
on device flash.

Aside: removes "enable-webrtc-hw-decoding", which doesn't exist, and "enable-threaded-compositing", which is now enabled by default.

R=lcwu@chromium.org,damienv@chromium.org
BUG=336640

Review URL: https://codereview.chromium.org/468223004

Cr-Commit-Position: refs/heads/master@{#290022}
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@290022 0039d316-1c4b-4281-b951-d872f2087c98

chromecast/shell/browser/cast_browser_main_parts.cc

@@ -14,6 +14,7 @@
 #include "chromecast/shell/browser/devtools/remote_debugging_server.h"
 #include "chromecast/shell/browser/url_request_context_factory.h"
 #include "chromecast/shell/browser/webui/webui_cast.h"
+#include "content/public/common/content_switches.h"
 
 namespace chromecast {
 namespace shell {
@@ -26,9 +27,8 @@ struct DefaultCommandLineSwitch {
 };
 
 DefaultCommandLineSwitch g_default_switches[] = {
-  { "enable-webrtc-hw-decoding", "" },
-  { "disable-plugins", "" },
-  { "enable-threaded-compositing", "" },
+  { switches::kDisableApplicationCache, "" },
+  { switches::kDisablePlugins, "" },
   { NULL, NULL },  // Termination
 };