The Transparency Report website has been redesigned. The new location for that link is https://transparencyreport.google.com/safe-browsing/search.  Automated links for particular sites should go to 
https://transparencyreport.google.com/safe-browsing/search?url=example.com

+hibbert@, ppdeeksha@,
The old link "https://www.google.com/safebrowsing/diagnostic?site=a.com&client=googlechrome&hl=en-US"  takes in a "client" parameter to distinguish users of Google Chrome build and Chromium build. The new link seems not accept this parameter. Does this mean that diagnostic page doesn't care about this info any more? 

And can I assume the locale info should be passed along in the same way (using "hl=") as the old link? 

The client parameter is no longer supported. If there was functionality there that should be revived, let me know.

The current page will honor hl= parameters, so if you have the value, please pass it on. I think we're expecting to migrate to a different approach in the next several weeks.  

laefer@ has more context on that. Jay, will we be passing language context as a query param when we're completely switched to ULS?

The hl= parameter will continue to be honored indefinitely. Please include it in any redirects. However, please do not add an hl= parameter if one was not previously being sent because it may override other user preferences.

If you have more questions, please let me know.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/7aa106537352b35bf971df2818b9dd925e03c78e

commit 7aa106537352b35bf971df2818b9dd925e03c78e
Author: Jialiu Lin <jialiul@chromium.org>
Date: Tue Nov 14 23:33:29 2017

Add/Update diagnostic links on SB interstitials

1. The diagnostic link is included in the detail section in malware and
UwS interstitial, but somehow is missing from the phishing
interstitial. This change fixes this problem.
2. This change also migrates the diagnostic link into a new URL

Bug:  758809 
Change-Id: I3dad307bacd7fa0030587138f4bdeb0578652c4b
Reviewed-on: https://chromium-review.googlesource.com/754057
Commit-Queue: Jialiu Lin <jialiul@chromium.org>
Reviewed-by: Nate Fischer <ntfschr@chromium.org>
Reviewed-by: Nathan Parker <nparker@chromium.org>
Cr-Commit-Position: refs/heads/master@{#516498}
[modify] https://crrev.com/7aa106537352b35bf971df2818b9dd925e03c78e/android_webview/javatests/src/org/chromium/android_webview/test/SafeBrowsingTest.java
[modify] https://crrev.com/7aa106537352b35bf971df2818b9dd925e03c78e/components/security_interstitials/core/safe_browsing_loud_error_ui.cc
[modify] https://crrev.com/7aa106537352b35bf971df2818b9dd925e03c78e/components/security_interstitials_strings.grdp