[Payments] Add PaymentRequest checkout funnel UKMs.

components/payments/core/journey_logger.h

Index: components/payments/core/journey_logger.h
diff --git a/components/payments/core/journey_logger.h b/components/payments/core/journey_logger.h
index 67401c1ec4af961ca11b371d1d135fe6f5655730..99bf3720a1d62e76a1af5884bc7ce716d9d62971 100644
--- a/components/payments/core/journey_logger.h
+++ b/components/payments/core/journey_logger.h
@@ -8,6 +8,18 @@
 #include <string>
 
 #include "base/macros.h"
+#include "url/gurl.h"
+
+namespace ukm {
+class UkmService;
+}
+
+namespace internal {

[please use gerrit instead, 2017/04/10 19:20:03]

Put this inside of payments namespace please.

[sebsg, 2017/04/10 19:49:53]

Done.

+// Name constants are exposed here so they can be referenced from tests.
+extern const char kUKMCheckoutFunnelEntryName[];
+extern const char kUKMCompletionStatusMetricName[];
+extern const char kUKMLastStepMetricName[];
+}  // namespace internal
 
 namespace payments {
 
@@ -46,6 +58,16 @@ class JourneyLogger {
     COMPLETION_STATUS_MAX,
   };
 
+  // Used to record the different events that happened during the Payment
+  // Request.
+  enum Event {
+    EVENT_INITIATED = 0,
+    EVENT_SHOWN = 1 << 0,
+    EVENT_PAY_CLICKED = 1 << 1,
+    EVENT_RECEIVED_INSTRUMENT_DETAILS = 1 << 2,
+    EVENT_MAX = 8,
+  };
+
   // Used to mesure the impact of the CanMakePayment return value on whether the
   // Payment Request is shown to the user.
   static const int CMP_SHOW_COULD_NOT_MAKE_PAYMENT_AND_DID_NOT_SHOW = 0;
@@ -53,7 +75,7 @@ class JourneyLogger {
   static const int CMP_SHOW_COULD_MAKE_PAYMENT = 1 << 1;
   static const int CMP_SHOW_MAX = 4;
 
-  explicit JourneyLogger(bool is_incognito);
+  JourneyLogger(bool is_incognito, GURL url, ukm::UkmService* ukm_service);

[please use gerrit instead, 2017/04/10 19:20:03]

url should be const-ref.

[please use gerrit instead, 2017/04/10 19:20:03]

Add a comment about life time expectations for ukm_service.

[sebsg, 2017/04/10 19:49:52]

Added the comment on the stored pointer, seems like that's the convention
looking at payment_request_state.h for example.

[sebsg, 2017/04/10 19:49:52]

Done.

   ~JourneyLogger();
 
   // Increments the number of selection adds for the specified section.
@@ -75,6 +97,9 @@ class JourneyLogger {
   // Records the fact that the Payment Request was shown to the user.
   void SetShowCalled();
 
+  // Records that an event occurred.
+  void SetEventOccurred(Event event);
+
   // Records the histograms for all the sections that were requested by the
   // merchant and for the usage of the CanMakePayment method and its effect on
   // the transaction. This method should be called when the Payment Request has
@@ -125,12 +150,21 @@ class JourneyLogger {
   void RecordCanMakePaymentEffectOnCompletion(
       CompletionStatus completion_status);
 
+  // Records the Payment Request Url Keyed Metrics.
+  void RecordUrlKeyedMetrics(CompletionStatus completion_status);
+
   SectionStats sections_[NUMBER_OF_SECTIONS];
   bool was_can_make_payments_used_;
   bool could_make_payment_;
   bool was_show_called_;
   bool is_incognito_;
 
+  // Accumulates the many event that have happened during the Payment Request.

[Mathieu, 2017/04/10 19:03:15]

*events

[sebsg, 2017/04/10 19:49:52]

Done.

+  int events_;
+
+  GURL url_;
+  ukm::UkmService* ukm_service_;
+
   DISALLOW_COPY_AND_ASSIGN(JourneyLogger);
 };