Store Origin Trials public key in browser prefs

content/public/common/content_client.h

Index: content/public/common/content_client.h
diff --git a/content/public/common/content_client.h b/content/public/common/content_client.h
index f0862d5b40ac4d16b6bc2b3aa3d8b60f499455d2..5510cb27f9145e769ea02cf7df17502e72cafe1a 100644
--- a/content/public/common/content_client.h
+++ b/content/public/common/content_client.h
@@ -168,6 +168,11 @@ class CONTENT_EXPORT ContentClient {
   // model decisions.
   virtual bool IsSupplementarySiteIsolationModeEnabled();
 
+  // Called by the renderer after the render thread has started, and allows the
+  // embedder to set up any global origin trial policies (custom public key, or
+  // disabled experiments)
+  virtual void InitializeOriginTrialPolicy();
+
   // Returns the public key to be used for origin trials, or an empty string if
   // origin trials are not enabled in this context.
   virtual base::StringPiece GetOriginTrialPublicKey();