Add UMA for the number of devices in the chooser when a device is paired

content/browser/bluetooth/bluetooth_metrics.cc

Index: content/browser/bluetooth/bluetooth_metrics.cc
diff --git a/content/browser/bluetooth/bluetooth_metrics.cc b/content/browser/bluetooth/bluetooth_metrics.cc
index 7a0b4722f7dd4bb77a30d4ca8497935cb0690ba4..6ae97006a59a33d63af9d0f41dae3967840639ef 100644
--- a/content/browser/bluetooth/bluetooth_metrics.cc
+++ b/content/browser/bluetooth/bluetooth_metrics.cc
@@ -6,6 +6,7 @@
 
 #include <stdint.h>
 
+#include <algorithm>
 #include <map>
 #include <set>
 #include <unordered_set>
@@ -42,6 +43,9 @@ int HashUUID(const base::Optional<BluetoothUUID>& uuid) {
   return uuid ? HashUUID(uuid->canonical_value()) : 0;
 }
 
+// The maximum number of devices that needs to be recorded.
+const size_t kMaxNumOfDevices = 100;
+
 }  // namespace
 
 namespace content {
@@ -353,4 +357,13 @@ void RecordRSSISignalStrengthLevel(UMARSSISignalStrengthLevel level) {
       static_cast<int>(UMARSSISignalStrengthLevel::COUNT));
 }
 
+void RecordNumOfDevices(bool accept_all_devices, size_t num_of_devices) {
+  if (accept_all_devices) {
+    UMA_HISTOGRAM_SPARSE_SLOWLY(
+        "Bluetooth.Web.RequestDevice."
+        "NumOfDevicesInChooserWhenNotAcceptingAllDevices",
+        std::min(num_of_devices, kMaxNumOfDevices));
+  }
+}
+
 }  // namespace content