Generate all extension schema namespaces as "api" and instead vary the generated bundle names.

extensions/common/api/printer_provider/usb_printer_manifest_data.cc

Index: extensions/common/api/printer_provider/usb_printer_manifest_data.cc
diff --git a/extensions/common/api/printer_provider/usb_printer_manifest_data.cc b/extensions/common/api/printer_provider/usb_printer_manifest_data.cc
index 4cfca0082fb140f713b6dce0593ba2bb57718138..79c1eed27853dfbcdbedf509860aacfe61c01cc7 100644
--- a/extensions/common/api/printer_provider/usb_printer_manifest_data.cc
+++ b/extensions/common/api/printer_provider/usb_printer_manifest_data.cc
@@ -31,8 +31,8 @@ const UsbPrinterManifestData* UsbPrinterManifestData::Get(
 scoped_ptr<UsbPrinterManifestData> UsbPrinterManifestData::FromValue(
     const base::Value& value,
     base::string16* error) {
-  scoped_ptr<core_api::extensions_manifest_types::UsbPrinters> usb_printers =
-      core_api::extensions_manifest_types::UsbPrinters::FromValue(value, error);
+  scoped_ptr<api::extensions_manifest_types::UsbPrinters> usb_printers =
+      api::extensions_manifest_types::UsbPrinters::FromValue(value, error);
   if (!usb_printers) {
     return nullptr;
   }