Pass Physical Web metadata through a struct

chrome/browser/android/physical_web/physical_web_data_source_android.h

Index: chrome/browser/android/physical_web/physical_web_data_source_android.h
diff --git a/chrome/browser/android/physical_web/physical_web_data_source_android.h b/chrome/browser/android/physical_web/physical_web_data_source_android.h
index 7704082a58556e9b736b1a1f61eb7cfa46f560cb..6e08e3866e6d1e529941f3e8213d0e9d645f0f33 100644
--- a/chrome/browser/android/physical_web/physical_web_data_source_android.h
+++ b/chrome/browser/android/physical_web/physical_web_data_source_android.h
@@ -27,7 +27,7 @@ class PhysicalWebCollection {
       const base::android::JavaParamRef<jobject>& obj,
       const base::android::JavaParamRef<jstring>& j_request_url,
       jdouble distance_estimate,
-      jint scan_timestamp,
+      jlong scan_timestamp,
       const base::android::JavaParamRef<jstring>& j_site_url,
       const base::android::JavaParamRef<jstring>& j_icon_url,
       const base::android::JavaParamRef<jstring>& j_title,
@@ -36,10 +36,17 @@ class PhysicalWebCollection {
 
   // Returns the metadata list and transfers ownership of the list to the
   // caller. Call only once.
-  std::unique_ptr<base::ListValue> GetMetadataList();
+  std::unique_ptr<physical_web::MetadataList> GetMetadataList();
+
+  // Returns the metadata list and transfers ownership of the list to the
+  // caller. Call only once.
+  // DEPRECATED
+  // TODO(cco3): Remove when we no longer rely on this.
+  std::unique_ptr<base::ListValue> GetMetadataListValue();
 
  private:
-  std::unique_ptr<base::ListValue> metadata_list_;
+  std::unique_ptr<base::ListValue> dictionary_value_list_;
+  std::unique_ptr<physical_web::MetadataList> metadata_list_;
   bool accessed_once_;
 
   DISALLOW_COPY_AND_ASSIGN(PhysicalWebCollection);
@@ -59,6 +66,7 @@ class PhysicalWebDataSourceAndroid
   void StopDiscovery() override;
 
   std::unique_ptr<base::ListValue> GetMetadata() override;
+  std::unique_ptr<physical_web::MetadataList> GetMetadataList() override;

[nyquist, 2016/12/13 18:13:25]

The naming of these methods do not seem consistent. GetMetaDataList seems like
the new thing, but GetMetadata and GetMetadataListValue are both referring to
base::ListValue. Could we use the same method name for the same thing across
this?

[cco3, 2016/12/16 19:17:53]

Good catch.  The whole ListValue thing is temporary (hopefully will be gone in a
few weeks) and I went through too stages of naming it.

   bool HasUnresolvedDiscoveries() override;
 
   void OnFound(JNIEnv* env,