Don't tell people they can import their own roots on iOS.

chrome/app/generated_resources.grd

Index: chrome/app/generated_resources.grd
diff --git a/chrome/app/generated_resources.grd b/chrome/app/generated_resources.grd
index c59cb19454ff5f70f4512c552328ffffb2615d8c..747467610e1f3fad15bf86d554e8b54ce6440354 100644
--- a/chrome/app/generated_resources.grd
+++ b/chrome/app/generated_resources.grd
@@ -3357,6 +3357,8 @@ Psst! Incognito mode <ph name="SHORTCUT_KEY">$1<ex>(Ctrl+Shift+N)</ex></ph> may
         <message name="IDS_CERT_ERROR_AUTHORITY_INVALID_EXTRA_INFO_2" desc="Mobile: 2nd paragraph of extra information for a X509 certificate with an invalid authority">
           In this case, the certificate has not been verified by a third party that your mobile device trusts. Anyone can create a certificate claiming to be whatever website they choose, which is why it must be verified by a trusted third party. Without that verification, the identity information in the certificate is meaningless. It is therefore not possible to verify that you are communicating with <ph name="DOMAIN">&lt;strong&gt;$1<ex>paypal.com</ex>&lt;/strong&gt;</ph> instead of an attacker who generated his own certificate claiming to be <ph name="DOMAIN2">&lt;strong&gt;$2<ex>paypal.com</ex>&lt;/strong&gt;</ph>. You should not proceed past this point.
         </message>
+      </if>
+      <if expr="pp_ifdef('android')">
         <message name="IDS_CERT_ERROR_AUTHORITY_INVALID_EXTRA_INFO_3" desc="Mobile: 3rd paragraph of extra information for a X509 certificate with an invalid authority">
           If, however, you work in an organization that generates its own certificates, and you are trying to connect to an internal website of that organization using such a certificate, you may be able to solve this problem securely. You can import your organization's root certificate as a "root certificate", and then certificates issued or verified by your organization will be trusted and you will not see this error next time you try to connect to an internal website. Contact your organization's help staff for assistance in adding a new root certificate to your mobile device.
         </message>