Reporting: Add histograms.

content/browser/net/reporting_service_proxy.cc

Index: content/browser/net/reporting_service_proxy.cc
diff --git a/content/browser/net/reporting_service_proxy.cc b/content/browser/net/reporting_service_proxy.cc
index 2e41335c11393e721213cd0c9043bcefc4bbe938..61dcf893f524e2b85cb1830563a48da65f9aeacc 100644
--- a/content/browser/net/reporting_service_proxy.cc
+++ b/content/browser/net/reporting_service_proxy.cc
@@ -15,6 +15,7 @@
 #include "content/public/browser/site_instance.h"
 #include "content/public/browser/storage_partition.h"
 #include "mojo/public/cpp/bindings/strong_binding.h"
+#include "net/reporting/reporting_report.h"
 #include "net/reporting/reporting_service.h"
 #include "net/url_request/url_request_context.h"
 #include "net/url_request/url_request_context_getter.h"
@@ -45,13 +46,17 @@ void QueueReportOnIOThread(
     std::unique_ptr<const base::Value> body) {
   net::URLRequestContext* request_context =
       request_context_getter->GetURLRequestContext();
-  if (!request_context)
+  if (!request_context) {
+    net::ReportingReport::RecordReportDiscardedForNoURLRequestContext();
     return;
+  }
 
   net::ReportingService* reporting_service =
       request_context->reporting_service();
-  if (!reporting_service)
+  if (!reporting_service) {
+    net::ReportingReport::RecordReportDiscardedForNoReportingService();
     return;
+  }
 
   // TODO(juliatuttle): Get rid of this copy.
   reporting_service->QueueReport(url, group, type, body->CreateDeepCopy());
@@ -69,8 +74,10 @@ class ReportingServiceProxyImpl : public mojom::ReportingServiceProxy {
                    mojom::ReportingReportType type_enum,
                    std::unique_ptr<base::Value> body) override {
     std::string type_string = ReportTypeEnumToString(type_enum);
-    if (type_string.empty())
+    if (type_string.empty()) {
+      net::ReportingReport::RecordReportDiscardedForInvalidTypeFromRenderer();
       return;
+    }
 
     // TODO(juliatuttle): Get rid of this intermediate step.
     const base::Value* raw_const_body = body.release();