Introduce an extension parameter which is used to customize the extension. It's available for exter…

chrome/browser/extensions/external_registry_loader_win.cc

Index: chrome/browser/extensions/external_registry_loader_win.cc
diff --git a/chrome/browser/extensions/external_registry_loader_win.cc b/chrome/browser/extensions/external_registry_loader_win.cc
index d988f49bc90e0c10e91d3e9982350eefb3f15c52..5bd56179fd553b3be091b46fa921e62e41358d2d 100644
--- a/chrome/browser/extensions/external_registry_loader_win.cc
+++ b/chrome/browser/extensions/external_registry_loader_win.cc
@@ -26,6 +26,9 @@ namespace {
 // The Registry subkey that contains information about external extensions.
 const char kRegistryExtensions[] = "Software\\Google\\Chrome\\Extensions";
 
+// Registry value of the key that defines the installation parameter.
+const wchar_t kRegistryExtensionInstallParam[] = L"install_parameter";
+
 // Registry value of the key that defines the path to the .crx file.
 const wchar_t kRegistryExtensionPath[] = L"path";
 
@@ -94,6 +97,13 @@ void ExternalRegistryLoader::LoadOnFileThread() {
       continue;
     }
 
+    base::string16 extension_dist_id;
+    if (key.ReadValue(kRegistryExtensionInstallParam, &extension_dist_id) ==
+        ERROR_SUCCESS) {
+      prefs->SetString(id + "." + ExternalProviderImpl::kInstallParam,
+                       base::UTF16ToASCII(extension_dist_id));
+    }
+
     // If there is an update URL present, copy it to prefs and ignore
     // path and version keys for this entry.
     base::string16 extension_update_url;