Do not show the install prompt for themes.

chrome/browser/extensions/extension_webstore_private_api.cc

Index: chrome/browser/extensions/extension_webstore_private_api.cc
diff --git a/chrome/browser/extensions/extension_webstore_private_api.cc b/chrome/browser/extensions/extension_webstore_private_api.cc
index f53abfff9d8afd50e6017b2b641011b7e5e7801f..b9f64d5f8d4d3fa0e3c21dd869cc1db931a4d3e1 100644
--- a/chrome/browser/extensions/extension_webstore_private_api.cc
+++ b/chrome/browser/extensions/extension_webstore_private_api.cc
@@ -250,7 +250,7 @@ void InstallBundleFunction::OnBundleInstallCompleted() {
 }
 
 BeginInstallWithManifestFunction::BeginInstallWithManifestFunction()
-  : use_app_installed_bubble_(false) {}
+    : use_app_installed_bubble_(false) {}
 
 BeginInstallWithManifestFunction::~BeginInstallWithManifestFunction() {}
 
@@ -357,23 +357,18 @@ void BeginInstallWithManifestFunction::OnWebstoreParseSuccess(
   icon_ = icon;
   parsed_manifest_.reset(parsed_manifest);
 
-  ExtensionInstallUI::Prompt prompt(ExtensionInstallUI::INSTALL_PROMPT);
-
-  if (!ShowExtensionInstallDialogForManifest(
-      profile(),
-      this,
-      parsed_manifest,
-      id_,
-      localized_name_,
-      "", // no localized description
-      &icon_,
-      prompt,
-      &dummy_extension_)) {
+  std::string error;
+  dummy_extension_ = ExtensionInstallUI::LocalizeExtensionForDisplay(
+      parsed_manifest_.get(), id, localized_name_, "", &error);
+
+  if (!dummy_extension_) {
     OnWebstoreParseFailure(id_, WebstoreInstallHelper::Delegate::MANIFEST_ERROR,
                            kInvalidManifestError);
     return;
   }
 
+  install_ui_.reset(new ExtensionInstallUI(profile()));
+  install_ui_->ConfirmWebstoreInstall(this, dummy_extension_, &icon_);
   // Control flow finishes up in InstallUIProceed or InstallUIAbort.
 }