Create a temp download directory for WebstorePrivateApiTest

This test was writing to the user's downloads directory instead of a
temporary path.

BUG=372017
R=asargent@chromium.org

Review URL: https://codereview.chromium.org/274193008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@269607 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/extensions/api/webstore_private/webstore_private_apitest.cc

@@ -157,6 +157,11 @@ class ExtensionWebstorePrivateApiTest : public ExtensionApiTest {
             ProfileOAuth2TokenServiceFactory::GetInstance()->GetForProfile(
                 profile()));
     ASSERT_TRUE(token_service_);
+
+    ASSERT_TRUE(webstore_install_dir_.CreateUniqueTempDir());
+    webstore_install_dir_copy_ = webstore_install_dir_.path();
+    WebstoreInstaller::SetDownloadDirectoryForTests(
+        &webstore_install_dir_copy_);
   }
 
  protected:
@@ -223,6 +228,10 @@ class ExtensionWebstorePrivateApiTest : public ExtensionApiTest {
   scoped_ptr<base::CallbackList<void(content::BrowserContext*)>::Subscription>
       will_create_browser_context_services_subscription_;
 
+  base::ScopedTempDir webstore_install_dir_;
+  // WebstoreInstaller needs a reference to a FilePath when setting the download
+  // directory for testing.
+  base::FilePath webstore_install_dir_copy_;
 };
 
 // Test cases for webstore origin frame blocking.