OpenID: Remove support for Yahoo! OpenID provider

Yahoo! discontinued support for OpenID provider: [1]

"OpenID2 will be EOLed on 6/30/20"

[1] https://developer.yahoo.com/oauth2/guide/OpenID2

Bug: Issue 13140
Bug: Issue 14330
Change-Id: I49a3adf5a331f119af8393d2403e98a7b3dcd654
diff --git a/Documentation/config-sso.txt b/Documentation/config-sso.txt
index 6f3a32d..88de85e 100644
--- a/Documentation/config-sso.txt
+++ b/Documentation/config-sso.txt
@@ -43,9 +43,9 @@
 * `http://` -- trust all OpenID providers using the HTTP protocol
 * `https://` -- trust all OpenID providers using the HTTPS protocol
 
-To trust only Yahoo!:
+To trust only Launchpad:
 ----
-  git config --file $site_path/etc/gerrit.config auth.trustedOpenID https://me.yahoo.com
+  git config --file $site_path/etc/gerrit.config auth.trustedOpenID https://login.launchpad.net/+openid
 ----
 
 === Database Schema
diff --git a/Documentation/dev-design.txt b/Documentation/dev-design.txt
index fd53cac..0243a58 100644
--- a/Documentation/dev-design.txt
+++ b/Documentation/dev-design.txt
@@ -255,11 +255,7 @@
 
 Gerrit integrates with any OpenID provider for user authentication,
 making it easier for users to join a Gerrit site and manage their
-authentication credentials to it.  To make use of Google Accounts
-as an OpenID provider easier, Gerrit has a shorthand "Sign in with
-a Google Account" link on its sign-in screen.  Gerrit also supports
-a shorthand sign in link for Yahoo!.  Other providers may also be
-supported more directly in the future.
+authentication credentials to it.
 
 Site administrators may limit the range of OpenID providers to
 a subset of "reliable providers".  Users may continue to use
diff --git a/java/com/google/gerrit/common/auth/openid/OpenIdUrls.java b/java/com/google/gerrit/common/auth/openid/OpenIdUrls.java
index 713fd4d..16dfb9b 100644
--- a/java/com/google/gerrit/common/auth/openid/OpenIdUrls.java
+++ b/java/com/google/gerrit/common/auth/openid/OpenIdUrls.java
@@ -18,5 +18,4 @@
   public static final String LASTID_COOKIE = "gerrit.last_openid";
 
   public static final String URL_LAUNCHPAD = "https://login.launchpad.net/+openid";
-  public static final String URL_YAHOO = "https://me.yahoo.com";
 }
diff --git a/java/com/google/gerrit/httpd/auth/openid/LoginForm.java b/java/com/google/gerrit/httpd/auth/openid/LoginForm.java
index 283cd50..0b6008c 100644
--- a/java/com/google/gerrit/httpd/auth/openid/LoginForm.java
+++ b/java/com/google/gerrit/httpd/auth/openid/LoginForm.java
@@ -59,9 +59,7 @@
   private static final FluentLogger logger = FluentLogger.forEnclosingClass();
 
   private static final ImmutableMap<String, String> ALL_PROVIDERS =
-      ImmutableMap.of(
-          "launchpad", OpenIdUrls.URL_LAUNCHPAD,
-          "yahoo", OpenIdUrls.URL_YAHOO);
+      ImmutableMap.of("launchpad", OpenIdUrls.URL_LAUNCHPAD);
 
   private final ImmutableSet<String> suggestProviders;
   private final Provider<String> urlProvider;
diff --git a/resources/com/google/gerrit/httpd/auth/openid/LoginForm.html b/resources/com/google/gerrit/httpd/auth/openid/LoginForm.html
index 4923143..efd760f 100644
--- a/resources/com/google/gerrit/httpd/auth/openid/LoginForm.html
+++ b/resources/com/google/gerrit/httpd/auth/openid/LoginForm.html
@@ -75,11 +75,6 @@
           <a href="?id=https://login.launchpad.net/%2Bopenid" id="id_launchpad">Sign in with a Launchpad ID</a>
         </div>
 
-        <div id="provider_yahoo">
-          <img height="16" width="16" src="data:image/gif;base64,R0lGODlhEAAQAPECAAAAAP8AAP///8zMzCH5BAEAAAMALAAAAAAQABAAAAIqnI+py30BY3AgAjCkfJDjiIAQlgUkNxqWkqrm0honKk7KhZOzw/f+fygAADs=" />
-          <a href="?id=https://me.yahoo.com" id="id_yahoo">Sign in with a Yahoo! ID</a>
-        </div>
-
         <div style="margin-top: 25px;">
           <h2>What is OpenID?</h2>
           <p>OpenID provides secure single-sign-on, without revealing your passwords to this website.</p>