I received a notice from Google on March 22, 2018, informing that they would be adopting the European GPDR. This will affect all their core services (including Gmail, and all of their advertising and measurement services like AdWords, AdSense, DoubleClick and Analytics) and will take place on May 25, 2018.
Updated EU User Consent Policy
Google's EU User Consent Policy is being updated to reflect the new legal requirements of the GDPR. It sets out your responsibilities for making disclosures to, and obtaining consents from, end users in the EEA. For example, under that policy, advertisers will be required to obtain consent from users for the collection of data for personalized ads (e.g. remarketing tags to build audience lists) and for the use of cookies where legally required (e.g. conversion tags). The policy is incorporated into the contracts for most Google ads and measurement products globally. [Emphasis mine]
Here is the EU Consent Policy (which is currently being updated).