Add a Physical Web data source

ios/chrome/common/physical_web/physical_web_scanner.h

Index: ios/chrome/common/physical_web/physical_web_scanner.h
diff --git a/ios/chrome/common/physical_web/physical_web_scanner.h b/ios/chrome/common/physical_web/physical_web_scanner.h
index 8f28f90ce857792e00dd7d513c5d1e28635c1a20..08ddf133d2087012f4d9f5b9fc7ebff734f60c39 100644
--- a/ios/chrome/common/physical_web/physical_web_scanner.h
+++ b/ios/chrome/common/physical_web/physical_web_scanner.h
@@ -7,7 +7,9 @@
 
 #import <Foundation/Foundation.h>
 
-@class PhysicalWebDevice;
+#include <memory>
+
+#include "base/values.h"

[sdefresne, 2016/08/04 19:23:48]

nit: I think we can forward-declare base::ListValue here and remove this
include.

[mattreynolds, 2016/08/04 21:14:34]

Done.

 
 @protocol PhysicalWebScannerDelegate;
 
@@ -43,6 +45,9 @@
 // Returns a list of physical web devices (PhysicalWebDevice).
 - (NSArray*)devices;
 
+// Returns the metadata for all resolved physical web URLs.

[sdefresne, 2016/08/04 19:23:47]

Can you say that the method always returns a non null value?

[mattreynolds, 2016/08/04 21:14:34]

Done.

+- (std::unique_ptr<base::ListValue>)metadata;
+
 @end
 
 @protocol PhysicalWebScannerDelegate<NSObject>