Generate Instance ID locally.

components/gcm_driver/instance_id/instance_id_impl.h

Index: components/gcm_driver/instance_id/instance_id_impl.h
diff --git a/components/gcm_driver/instance_id/instance_id_impl.h b/components/gcm_driver/instance_id/instance_id_impl.h
index 9855500bf0773f98d21812c197bebd031b22ddfc..be7b9fc9e8aae5167a9b794aa27b77aa30ac9e47 100644
--- a/components/gcm_driver/instance_id/instance_id_impl.h
+++ b/components/gcm_driver/instance_id/instance_id_impl.h
@@ -10,9 +10,14 @@
 
 #include "base/callback.h"
 #include "base/macros.h"
+#include "base/memory/scoped_ptr.h"
 #include "base/time/time.h"
 #include "components/gcm_driver/instance_id/instance_id.h"
 
+namespace crypto {
+class RSAPrivateKey;
+}  // namespace crypto
+
 namespace instance_id {
 
 // InstanceID implementation for desktop and iOS.
@@ -34,6 +39,17 @@ class InstanceIDImpl : public InstanceID {
   void DeleteID(const DeleteIDCallback& callback) override;
 
  private:
+  void EnsureIDGenerated();
+
+  // The Instance ID is based on the public/private key pair.
+  scoped_ptr<crypto::RSAPrivateKey> key_pair_;

[fgorski, 2015/04/30 22:13:12]

do we need to keep the key_pair_ around? what for?

[jianli, 2015/05/02 00:30:18]

Not needed any more.

+
+  // The generated Instance ID.
+  std::string id_;
+
+  // The time when the Instance ID has been generated.
+  base::Time creation_time_;
+
   DISALLOW_COPY_AND_ASSIGN(InstanceIDImpl);
 };