Carry the client ID from the database all the way through upload

minidump/minidump_extensions.h

Index: minidump/minidump_extensions.h
diff --git a/minidump/minidump_extensions.h b/minidump/minidump_extensions.h
index d0c2dcf8eca346708bf4e1ff7e763d948e7404b5..b2bb50ebae334c37a1867d48921b0500db0fa5e0 100644
--- a/minidump/minidump_extensions.h
+++ b/minidump/minidump_extensions.h
@@ -460,6 +460,18 @@ struct ALIGNAS(4) PACKED MinidumpCrashpadInfo {
   //! no need for any fields present in later versions.
   uint32_t version;
 
+  //! \brief A %UUID identifying the client that crashed.
+  //!
+  //! Client identification is within the scope of the application, but it is
+  //! expected that the identifier will be unique for an instance of Crashpad
+  //! monitoring an application or set of applications for a user. The
+  //! identifier shall remain stable over time.
+  //!
+  //! If no identifier is available, this field will contain zeroes.
+  //!
+  //! This field is present when #version is at least `1`.
+  UUID client_id;
+
   //! \brief A MinidumpSimpleStringDictionary pointing to strings interpreted as
   //!     key-value pairs.
   //!