[iOS] Add feature to intercept sign-in on Google web.

Intercepts a user tap on sign-in to display an account consistency
promo that is to be defined.

Bug: 1125631
Change-Id: Id8c84e066b0f9c5a3c61dd88de6716da75320bb0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2398523
Commit-Queue: Nohemi Fernandez <[email protected]>
Reviewed-by: Sylvain Defresne <[email protected]>
Reviewed-by: Alice Wang <[email protected]>
Cr-Commit-Position: refs/heads/master@{#805321}
diff --git a/ios/chrome/browser/prerender/preload_controller.mm b/ios/chrome/browser/prerender/preload_controller.mm
index 151b448..a5497c9 100644
--- a/ios/chrome/browser/prerender/preload_controller.mm
+++ b/ios/chrome/browser/prerender/preload_controller.mm
@@ -465,6 +465,10 @@
   [self schedulePrerenderCancel];
 }
 
+- (void)onShowConsistencyPromo {
+  [self schedulePrerenderCancel];
+}
+
 - (void)onAddAccount {
   [self schedulePrerenderCancel];
 }