Refactor OriginTrialPolicy to be an abstract interface in content/public/common

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 fa93cdcc713d76ecea30a69b6e5fbc4740e36613..ee3fd1095fac3dd2f003a7ebc0565192073b7e52 100644
--- a/content/public/common/content_client.h
+++ b/content/public/common/content_client.h
@@ -49,6 +49,7 @@ class ContentClient;
 class ContentGpuClient;
 class ContentRendererClient;
 class ContentUtilityClient;
+class OriginTrialPolicy;
 struct CdmInfo;
 struct PepperPluginInfo;
 
@@ -173,13 +174,9 @@ class CONTENT_EXPORT ContentClient {
   // 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() const;
-
-  // Returns true if the named experimental feature should be disabled in origin
-  // trials, even if a valid token is present.
-  virtual bool IsOriginTrialFeatureDisabled(base::StringPiece feature) const;
+  // Returns the origin trial policy, or nullptr if origin trials are not
+  // supported by the embedder.
+  virtual const OriginTrialPolicy* GetOriginTrialPolicy() const;
 
 #if defined(OS_ANDROID)
   // Returns true for clients like Android WebView that uses synchronous