Populate VisibleSecurityState::displayed_mixed_content on iOS

ios/chrome/browser/ssl/ios_chrome_security_state_model_client.cc

Index: ios/chrome/browser/ssl/ios_chrome_security_state_model_client.cc
diff --git a/ios/chrome/browser/ssl/ios_chrome_security_state_model_client.cc b/ios/chrome/browser/ssl/ios_chrome_security_state_model_client.cc
index 47d85bf30868a3b2eb113d713028a6e20765e7d4..d005c40c5961d86912d1803b4db1d164514b46e5 100644
--- a/ios/chrome/browser/ssl/ios_chrome_security_state_model_client.cc
+++ b/ios/chrome/browser/ssl/ios_chrome_security_state_model_client.cc
@@ -98,4 +98,8 @@ void IOSChromeSecurityStateModelClient::GetVisibleSecurityState(
   state->cert_status = ssl.cert_status;
   state->connection_status = ssl.connection_status;
   state->security_bits = ssl.security_bits;
+  state->displayed_mixed_content =

[Eugene But (OOO till 7-30), 2016/01/12 17:11:30]

FWIW the following code seems to be cleaner:

state->displayed_mixed_content =
    ssl.content_status & web::SSLStatus::DISPLAYED_INSECURE_CONTENT;

But it's up to you.

[blundell, 2016/01/13 10:40:46]

This is copied over from //chrome, going to leave as-is.

+      (ssl.content_status & web::SSLStatus::DISPLAYED_INSECURE_CONTENT)
+          ? true
+          : false;
 }