Add default config for IPH_PasswordsAccountStorage

This CL adds a default FeatureConfig for
kIPHPasswordsAccountStorageFeature. It also adds an about:flags entry
to enable the feature. This will make manual testing much easier.

Bug: 1115476
Change-Id: I30efa2fc4d3177fb47b363a8076a484d7eca630e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2352935
Auto-Submit: Marc Treib <[email protected]>
Commit-Queue: Tommy Nyquist <[email protected]>
Reviewed-by: Tommy Nyquist <[email protected]>
Cr-Commit-Position: refs/heads/master@{#799693}
diff --git a/chrome/browser/flag_descriptions.h b/chrome/browser/flag_descriptions.h
index f6dbf5e0..c46d99d 100644
--- a/chrome/browser/flag_descriptions.h
+++ b/chrome/browser/flag_descriptions.h
@@ -254,6 +254,9 @@
 extern const char kEnablePasswordsAccountStorageName[];
 extern const char kEnablePasswordsAccountStorageDescription[];
 
+extern const char kEnablePasswordsAccountStorageIPHName[];
+extern const char kEnablePasswordsAccountStorageIPHDescription[];
+
 extern const char kExperimentalAccessibilityLanguageDetectionName[];
 extern const char kExperimentalAccessibilityLanguageDetectionDescription[];