Add tracing to the primary suspects of latency in sharing code.

Bug: 1035433

Change-Id: Ib04f5413245aced84f5fea526841014ce6219459
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2019022
Commit-Queue: Michael van Ouwerkerk <mvanouwerkerk@chromium.org>
Reviewed-by: Richard Knoll <knollr@chromium.org>
Reviewed-by: Eric Seckler <eseckler@chromium.org>
Cr-Commit-Position: refs/heads/master@{#735014}

base/trace_event/builtin_categories.h

@@ -123,6 +123,7 @@
   X("sequence_manager")                                                  \
   X("service_manager")                                                   \
   X("ServiceWorker")                                                     \
+  X("sharing")                                                           \
   X("shell")                                                             \
   X("shortcut_viewer")                                                   \
   X("shutdown")                                                          \

chrome/browser/sharing/click_to_call/click_to_call_message_handler_android.cc

@@ -6,6 +6,7 @@
 
 #include "base/android/jni_string.h"
 #include "base/logging.h"
+#include "base/trace_event/trace_event.h"
 #include "chrome/android/chrome_jni_headers/ClickToCallMessageHandler_jni.h"
 #include "chrome/browser/sharing/proto/click_to_call_message.pb.h"
 #include "chrome/browser/sharing/proto/sharing_message.pb.h"
@@ -18,6 +19,8 @@ void ClickToCallMessageHandler::OnMessage(
     chrome_browser_sharing::SharingMessage message,
     SharingMessageHandler::DoneCallback done_callback) {
   DCHECK(message.has_click_to_call_message());
+  TRACE_EVENT0("sharing", "ClickToCallMessageHandler::OnMessage");
+
   std::string phone_number = message.click_to_call_message().phone_number();
   JNIEnv* env = base::android::AttachCurrentThread();
 

chrome/browser/sharing/shared_clipboard/shared_clipboard_message_handler.cc

@@ -8,6 +8,7 @@
 #include <string>
 
 #include "base/strings/utf_string_conversions.h"
+#include "base/trace_event/trace_event.h"
 #include "chrome/browser/sharing/proto/shared_clipboard_message.pb.h"
 #include "chrome/browser/sharing/proto/sharing_message.pb.h"
 #include "chrome/browser/sharing/sharing_device_source.h"
@@ -25,6 +26,7 @@ void SharedClipboardMessageHandler::OnMessage(
     chrome_browser_sharing::SharingMessage message,
     SharingMessageHandler::DoneCallback done_callback) {
   DCHECK(message.has_shared_clipboard_message());
+  TRACE_EVENT0("sharing", "SharedClipboardMessageHandler::OnMessage");
 
   ui::ScopedClipboardWriter(ui::ClipboardBuffer::kCopyPaste)
       .WriteText(base::UTF8ToUTF16(message.shared_clipboard_message().text()));

chrome/browser/sharing/shared_clipboard/shared_clipboard_message_handler_android.cc

@@ -5,6 +5,7 @@
 #include "chrome/browser/sharing/shared_clipboard/shared_clipboard_message_handler_android.h"
 
 #include "base/android/jni_string.h"
+#include "base/trace_event/trace_event.h"
 #include "chrome/android/chrome_jni_headers/SharedClipboardMessageHandler_jni.h"
 #include "ui/base/clipboard/clipboard_buffer.h"
 #include "ui/base/clipboard/scoped_clipboard_writer.h"
@@ -18,6 +19,9 @@ SharedClipboardMessageHandlerAndroid::~SharedClipboardMessageHandlerAndroid() =
 
 void SharedClipboardMessageHandlerAndroid::ShowNotification(
     const std::string& device_name) {
+  TRACE_EVENT0("sharing",
+               "SharedClipboardMessageHandlerAndroid::ShowNotification");
+
   JNIEnv* env = base::android::AttachCurrentThread();
   Java_SharedClipboardMessageHandler_showNotification(
       env, base::android::ConvertUTF8ToJavaString(env, device_name));

chrome/browser/sharing/shared_clipboard/shared_clipboard_message_handler_desktop.cc

@@ -7,6 +7,7 @@
 #include "base/guid.h"
 #include "base/strings/string16.h"
 #include "base/strings/utf_string_conversions.h"
+#include "base/trace_event/trace_event.h"
 #include "chrome/browser/notifications/notification_display_service.h"
 #include "chrome/browser/notifications/notification_display_service_factory.h"
 #include "chrome/grit/generated_resources.h"
@@ -26,6 +27,9 @@ SharedClipboardMessageHandlerDesktop::~SharedClipboardMessageHandlerDesktop() =
 
 void SharedClipboardMessageHandlerDesktop::ShowNotification(
     const std::string& device_name) {
+  TRACE_EVENT0("sharing",
+               "SharedClipboardMessageHandlerDesktop::ShowNotification");
+
   std::string notification_id = base::GenerateGUID();
 
   base::string16 notification_title =

chrome/browser/sharing/sharing_fcm_handler.cc

@@ -7,6 +7,7 @@
 #include "base/no_destructor.h"
 #include "base/strings/strcat.h"
 #include "base/time/time.h"
+#include "base/trace_event/trace_event.h"
 #include "chrome/browser/sharing/features.h"
 #include "chrome/browser/sharing/sharing_constants.h"
 #include "chrome/browser/sharing/sharing_fcm_sender.h"
@@ -85,6 +86,8 @@ void SharingFCMHandler::ShutdownHandler() {
 
 void SharingFCMHandler::OnMessage(const std::string& app_id,
                                   const gcm::IncomingMessage& message) {
+  TRACE_EVENT_BEGIN0("sharing", "SharingFCMHandler::OnMessage");
+
   base::TimeTicks message_received_time = base::TimeTicks::Now();
   std::string message_id = GetStrippedMessageId(message.message_id);
   chrome_browser_sharing::SharingMessage sharing_message;
@@ -92,23 +95,23 @@ void SharingFCMHandler::OnMessage(const std::string& app_id,
     LOG(ERROR) << "Failed to parse incoming message with id : " << message_id;
     return;
   }
-  DCHECK(sharing_message.payload_case() !=
+  chrome_browser_sharing::SharingMessage::PayloadCase payload_case =
+      sharing_message.payload_case();
+  DCHECK(payload_case !=
          chrome_browser_sharing::SharingMessage::PAYLOAD_NOT_SET)
       << "No payload set in SharingMessage received";
 
   chrome_browser_sharing::MessageType message_type =
-      SharingPayloadCaseToMessageType(sharing_message.payload_case());
-  LogSharingMessageReceived(sharing_message.payload_case());
+      SharingPayloadCaseToMessageType(payload_case);
+  LogSharingMessageReceived(payload_case);
 
   SharingMessageHandler* handler =
-      handler_registry_->GetSharingHandler(sharing_message.payload_case());
+      handler_registry_->GetSharingHandler(payload_case);
   if (!handler) {
-    LOG(ERROR) << "No handler found for payload : "
-               << sharing_message.payload_case();
+    LOG(ERROR) << "No handler found for payload : " << payload_case;
   } else {
     SharingMessageHandler::DoneCallback done_callback = base::DoNothing();
-    if (sharing_message.payload_case() !=
-        chrome_browser_sharing::SharingMessage::kAckMessage) {
+    if (payload_case != chrome_browser_sharing::SharingMessage::kAckMessage) {
       done_callback = base::BindOnce(
           &SharingFCMHandler::SendAckMessage, weak_ptr_factory_.GetWeakPtr(),
           std::move(message_id), message_type, GetTargetInfo(sharing_message),
@@ -118,6 +121,9 @@ void SharingFCMHandler::OnMessage(const std::string& app_id,
 
     handler->OnMessage(std::move(sharing_message), std::move(done_callback));
   }
+
+  TRACE_EVENT_END1("sharing", "SharingFCMHandler::OnMessage", "message_type",
+                   SharingMessageTypeToString(message_type));
 }
 
 void SharingFCMHandler::OnSendAcknowledged(const std::string& app_id,
@@ -164,6 +170,12 @@ void SharingFCMHandler::SendAckMessage(
     return;
   }
 
+  int trace_id = GenerateSharingTraceId();
+  TRACE_EVENT_NESTABLE_ASYNC_BEGIN1(
+      "sharing", "Sharing.SendAckMessage", TRACE_ID_LOCAL(trace_id),
+      "original_message_type",
+      SharingMessageTypeToString(original_message_type));
+
   chrome_browser_sharing::SharingMessage sharing_message;
   chrome_browser_sharing::AckMessage* ack_message =
       sharing_message.mutable_ack_message();
@@ -178,17 +190,22 @@ void SharingFCMHandler::SendAckMessage(
       base::BindOnce(&SharingFCMHandler::OnAckMessageSent,
                      weak_ptr_factory_.GetWeakPtr(),
                      std::move(original_message_id), original_message_type,
-                     sender_device_type));
+                     sender_device_type, trace_id));
 }
 
 void SharingFCMHandler::OnAckMessageSent(
     std::string original_message_id,
     chrome_browser_sharing::MessageType original_message_type,
     SharingDevicePlatform sender_device_type,
+    int trace_id,
     SharingSendMessageResult result,
     base::Optional<std::string> message_id) {
   LogSendSharingAckMessageResult(original_message_type, sender_device_type,
                                  result);
   if (result != SharingSendMessageResult::kSuccessful)
     LOG(ERROR) << "Failed to send ack mesage for " << original_message_id;
+
+  TRACE_EVENT_NESTABLE_ASYNC_END1("sharing", "Sharing.SendAckMessage",
+                                  TRACE_ID_LOCAL(trace_id), "result",
+                                  SharingSendMessageResultToString(result));
 }

chrome/browser/sharing/sharing_fcm_handler.h

@@ -79,6 +79,7 @@ class SharingFCMHandler : public gcm::GCMAppHandler {
       std::string original_message_id,
       chrome_browser_sharing::MessageType original_message_type,
       SharingDevicePlatform sender_device_type,
+      int trace_id,
       SharingSendMessageResult result,
       base::Optional<std::string> message_id);
 

chrome/browser/sharing/sharing_fcm_handler_unittest.cc

@@ -17,6 +17,7 @@
 #include "components/sync_device_info/device_info.h"
 #include "components/sync_device_info/fake_device_info_sync_service.h"
 #include "components/sync_preferences/testing_pref_service_syncable.h"
+#include "content/public/test/browser_task_environment.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
@@ -129,6 +130,8 @@ class SharingFCMHandlerTest : public testing::Test {
     return incoming_message;
   }
 
+  content::BrowserTaskEnvironment task_environment_;
+
   FakeSharingHandlerRegistry handler_registry_;
 
   testing::NiceMock<MockSharingMessageHandler> mock_sharing_message_handler_;

chrome/browser/sharing/sharing_fcm_sender.cc

@@ -30,6 +30,8 @@ void SharingFCMSender::SendMessageToTargetInfo(
     base::TimeDelta time_to_live,
     SharingMessage message,
     SendMessageCallback callback) {
+  TRACE_EVENT0("sharing", "SharingFCMSender::SendMessageToTargetInfo");
+
   base::Optional<SharingSyncPreference::FCMRegistration> fcm_registration =
       sync_preference_->GetFCMRegistration();
   if (!fcm_registration) {
@@ -64,6 +66,8 @@ void SharingFCMSender::DoSendMessageToDevice(const syncer::DeviceInfo& device,
                                              base::TimeDelta time_to_live,
                                              SharingMessage message,
                                              SendMessageCallback callback) {
+  TRACE_EVENT0("sharing", "SharingFCMSender::DoSendMessageToDevice");
+
   base::Optional<syncer::DeviceInfo::SharingTargetInfo> target_info =
       GetTargetInfo(device);
   if (!target_info) {
@@ -118,6 +122,8 @@ bool SharingFCMSender::SetMessageSenderInfo(SharingMessage* message) {
 void SharingFCMSender::OnMessageSent(SendMessageCallback callback,
                                      gcm::SendWebPushMessageResult result,
                                      base::Optional<std::string> message_id) {
+  TRACE_EVENT1("sharing", "SharingFCMSender::OnMessageSent", "result", result);
+
   SharingSendMessageResult send_message_result;
   switch (result) {
     case gcm::SendWebPushMessageResult::kSuccessful:

chrome/browser/sharing/sharing_message_sender.cc

@@ -7,6 +7,7 @@
 #include "base/guid.h"
 #include "base/stl_util.h"
 #include "base/task/post_task.h"
+#include "base/trace_event/trace_event.h"
 #include "chrome/browser/sharing/sharing_constants.h"
 #include "chrome/browser/sharing/sharing_metrics.h"
 #include "chrome/browser/sharing/sharing_sync_preference.h"
@@ -32,6 +33,13 @@ void SharingMessageSender::SendMessageToDevice(
   DCHECK(message.payload_case() !=
          chrome_browser_sharing::SharingMessage::kAckMessage);
 
+  int trace_id = GenerateSharingTraceId();
+  TRACE_EVENT_NESTABLE_ASYNC_BEGIN1(
+      "sharing", "Sharing.SendMessage", TRACE_ID_LOCAL(trace_id),
+      "message_type",
+      SharingMessageTypeToString(
+          SharingPayloadCaseToMessageType(message.payload_case())));
+
   std::string message_guid = base::GenerateGUID();
   chrome_browser_sharing::MessageType message_type =
       SharingPayloadCaseToMessageType(message.payload_case());
@@ -44,7 +52,7 @@ void SharingMessageSender::SendMessageToDevice(
       message_metadata_, message_guid,
       SentMessageMetadata(std::move(callback), base::TimeTicks::Now(),
                           message_type, receiver_device_platform,
-                          last_updated_age));
+                          last_updated_age, trace_id));
   DCHECK(inserted.second);
 
   auto delegate_iter = send_delegates_.find(delegate_type);
@@ -84,6 +92,8 @@ void SharingMessageSender::SendMessageToDevice(
   message.set_sender_device_name(
       send_tab_to_self::GetSharingDeviceNames(local_device_info).full_name);
 
+  TRACE_EVENT_NESTABLE_ASYNC_BEGIN0("sharing", "Sharing.DoSendMessage",
+                                    TRACE_ID_LOCAL(trace_id));
   delegate->DoSendMessageToDevice(
       device, response_timeout, std::move(message),
       base::BindOnce(&SharingMessageSender::OnMessageSent,
@@ -94,6 +104,10 @@ void SharingMessageSender::OnMessageSent(
     const std::string& message_guid,
     SharingSendMessageResult result,
     base::Optional<std::string> message_id) {
+  TRACE_EVENT_NESTABLE_ASYNC_END1(
+      "sharing", "Sharing.DoSendMessage",
+      TRACE_ID_LOCAL(message_metadata_.find(message_guid)->second.trace_id),
+      "result", SharingSendMessageResultToString(result));
   if (result != SharingSendMessageResult::kSuccessful) {
     InvokeSendMessageCallback(message_guid, result,
                               /*response=*/nullptr);
@@ -114,6 +128,7 @@ void SharingMessageSender::OnMessageSent(
 void SharingMessageSender::OnAckReceived(
     const std::string& message_id,
     std::unique_ptr<chrome_browser_sharing::ResponseMessage> response) {
+  TRACE_EVENT0("sharing", "SharingMessageSender::OnAckReceived");
   auto guid_iter = message_guids_.find(message_id);
   if (guid_iter == message_guids_.end()) {
     // We don't have the guid yet, store the response until we receive it.
@@ -159,6 +174,9 @@ void SharingMessageSender::InvokeSendMessageCallback(
   LogSendSharingMessageResult(metadata.type, metadata.receiver_device_platform,
                               result);
   LogSharingDeviceLastUpdatedAgeWithResult(result, metadata.last_updated_age);
+  TRACE_EVENT_NESTABLE_ASYNC_END1("sharing", "SharingMessageSender.SendMessage",
+                                  TRACE_ID_LOCAL(metadata.trace_id), "result",
+                                  SharingSendMessageResultToString(result));
 }
 
 SharingMessageSender::SentMessageMetadata::SentMessageMetadata(
@@ -166,12 +184,14 @@ SharingMessageSender::SentMessageMetadata::SentMessageMetadata(
     base::TimeTicks timestamp,
     chrome_browser_sharing::MessageType type,
     SharingDevicePlatform receiver_device_platform,
-    base::TimeDelta last_updated_age)
+    base::TimeDelta last_updated_age,
+    int trace_id)
     : callback(std::move(callback)),
       timestamp(timestamp),
       type(type),
       receiver_device_platform(receiver_device_platform),
-      last_updated_age(last_updated_age) {}
+      last_updated_age(last_updated_age),
+      trace_id(trace_id) {}
 
 SharingMessageSender::SentMessageMetadata::SentMessageMetadata(
     SentMessageMetadata&& other) = default;

chrome/browser/sharing/sharing_message_sender.h

@@ -84,7 +84,8 @@ class SharingMessageSender {
                         base::TimeTicks timestamp,
                         chrome_browser_sharing::MessageType type,
                         SharingDevicePlatform receiver_device_platform,
-                        base::TimeDelta last_updated_age);
+                        base::TimeDelta last_updated_age,
+                        int trace_id);
     SentMessageMetadata(SentMessageMetadata&& other);
     SentMessageMetadata& operator=(SentMessageMetadata&& other);
     ~SentMessageMetadata();
@@ -94,6 +95,7 @@ class SharingMessageSender {
     chrome_browser_sharing::MessageType type;
     SharingDevicePlatform receiver_device_platform;
     base::TimeDelta last_updated_age;
+    int trace_id;
   };
 
   void OnMessageSent(const std::string& message_guid,

chrome/browser/sharing/sharing_metrics.cc

@@ -9,6 +9,7 @@
 #include "base/strings/string_number_conversions.h"
 #include "chrome/browser/sharing/sharing_device_registration_result.h"
 #include "components/version_info/version_info.h"
+#include "content/public/browser/browser_thread.h"
 
 namespace {
 const char* GetEnumStringValue(SharingFeatureName feature) {
@@ -46,9 +47,20 @@ std::string DevicePlatformToString(SharingDevicePlatform device_platform) {
   }
 }
 
-// Maps SharingSendMessageResult enum values to strings used as histogram
-// suffixes. Keep in sync with "SharingSendMessageResult" in histograms.xml.
-std::string SendMessageResultToSuffix(SharingSendMessageResult result) {
+// Major Chrome version comparison with the receiver device.
+// These values are logged to UMA. Entries should not be renumbered and numeric
+// values should never be reused. Please keep in sync with
+// "SharingMajorVersionComparison" in enums.xml.
+enum class SharingMajorVersionComparison {
+  kUnknown = 0,
+  kSenderIsLower = 1,
+  kSame = 2,
+  kSenderIsHigher = 3,
+  kMaxValue = kSenderIsHigher,
+};
+}  // namespace
+
+std::string SharingSendMessageResultToString(SharingSendMessageResult result) {
   switch (result) {
     case SharingSendMessageResult::kSuccessful:
       return "Successful";
@@ -65,32 +77,6 @@ std::string SendMessageResultToSuffix(SharingSendMessageResult result) {
   }
 }
 
-const std::string& MessageTypeToMessageSuffix(
-    chrome_browser_sharing::MessageType message_type) {
-  // For proto3 enums unrecognized enum values are kept when parsing and their
-  // name is an empty string. We don't want to use that as a histogram suffix.
-  // The returned values must match the values of the SharingMessage suffixes
-  // defined in histograms.xml.
-  if (!chrome_browser_sharing::MessageType_IsValid(message_type)) {
-    return chrome_browser_sharing::MessageType_Name(
-        chrome_browser_sharing::UNKNOWN_MESSAGE);
-  }
-  return chrome_browser_sharing::MessageType_Name(message_type);
-}
-
-// Major Chrome version comparison with the receiver device.
-// These values are logged to UMA. Entries should not be renumbered and numeric
-// values should never be reused. Please keep in sync with
-// "SharingMajorVersionComparison" in enums.xml.
-enum class SharingMajorVersionComparison {
-  kUnknown = 0,
-  kSenderIsLower = 1,
-  kSame = 2,
-  kSenderIsHigher = 3,
-  kMaxValue = kSenderIsHigher,
-};
-}  // namespace
-
 chrome_browser_sharing::MessageType SharingPayloadCaseToMessageType(
     chrome_browser_sharing::SharingMessage::PayloadCase payload_case) {
   switch (payload_case) {
@@ -124,6 +110,23 @@ chrome_browser_sharing::MessageType SharingPayloadCaseToMessageType(
   return chrome_browser_sharing::UNKNOWN_MESSAGE;
 }
 
+const std::string& SharingMessageTypeToString(
+    chrome_browser_sharing::MessageType message_type) {
+  // For proto3 enums unrecognized enum values are kept when parsing and their
+  // name is an empty string. We don't want to use that as a histogram suffix.
+  if (!chrome_browser_sharing::MessageType_IsValid(message_type)) {
+    return chrome_browser_sharing::MessageType_Name(
+        chrome_browser_sharing::UNKNOWN_MESSAGE);
+  }
+  return chrome_browser_sharing::MessageType_Name(message_type);
+}
+
+int GenerateSharingTraceId() {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
+  static int next_id = 0;
+  return next_id++;
+}
+
 void LogSharingMessageReceived(
     chrome_browser_sharing::SharingMessage::PayloadCase payload_case) {
   base::UmaHistogramExactLinear("Sharing.MessageReceivedType",
@@ -218,11 +221,11 @@ void LogSharingMessageAckTime(chrome_browser_sharing::MessageType message_type,
                               SharingDevicePlatform receiver_device_platform,
                               base::TimeDelta time) {
   std::string suffixed_name = base::StrCat(
-      {"Sharing.MessageAckTime.", MessageTypeToMessageSuffix(message_type)});
+      {"Sharing.MessageAckTime.", SharingMessageTypeToString(message_type)});
   std::string platform_suffixed_name =
       base::StrCat({"Sharing.MessageAckTime.",
                     DevicePlatformToString(receiver_device_platform), ".",
-                    MessageTypeToMessageSuffix(message_type)});
+                    SharingMessageTypeToString(message_type)});
   switch (message_type) {
     case chrome_browser_sharing::MessageType::UNKNOWN_MESSAGE:
     case chrome_browser_sharing::MessageType::PING_MESSAGE:
@@ -251,7 +254,7 @@ void LogSharingMessageHandlerTime(
     base::TimeDelta time_taken) {
   base::UmaHistogramMediumTimes(
       base::StrCat({"Sharing.MessageHandlerTime.",
-                    MessageTypeToMessageSuffix(message_type)}),
+                    SharingMessageTypeToString(message_type)}),
       time_taken);
 }
 
@@ -262,7 +265,7 @@ void LogSharingDeviceLastUpdatedAge(
   int hours = age.InHours();
   base::UmaHistogramCounts1000(kBase, hours);
   base::UmaHistogramCounts1000(
-      base::StrCat({kBase, ".", MessageTypeToMessageSuffix(message_type)}),
+      base::StrCat({kBase, ".", SharingMessageTypeToString(message_type)}),
       hours);
 }
 
@@ -270,7 +273,7 @@ void LogSharingDeviceLastUpdatedAgeWithResult(SharingSendMessageResult result,
                                               base::TimeDelta age) {
   base::UmaHistogramCounts1000(
       base::StrCat({"Sharing.DeviceLastUpdatedAgeWithResult.",
-                    SendMessageResultToSuffix(result)}),
+                    SharingSendMessageResultToString(result)}),
       age.InHours());
 }
 
@@ -300,7 +303,7 @@ void LogSharingVersionComparison(
   constexpr char kBase[] = "Sharing.MajorVersionComparison";
   base::UmaHistogramEnumeration(kBase, result);
   base::UmaHistogramEnumeration(
-      base::StrCat({kBase, ".", MessageTypeToMessageSuffix(message_type)}),
+      base::StrCat({kBase, ".", SharingMessageTypeToString(message_type)}),
       result);
 }
 
@@ -319,7 +322,7 @@ void LogSendSharingMessageResult(
   base::UmaHistogramEnumeration(metric_prefix, result);
   base::UmaHistogramEnumeration(
       base::StrCat(
-          {metric_prefix, ".", MessageTypeToMessageSuffix(message_type)}),
+          {metric_prefix, ".", SharingMessageTypeToString(message_type)}),
       result);
 
   base::UmaHistogramEnumeration(
@@ -329,7 +332,7 @@ void LogSendSharingMessageResult(
   base::UmaHistogramEnumeration(
       base::StrCat({metric_prefix, ".",
                     DevicePlatformToString(receiving_device_platform), ".",
-                    MessageTypeToMessageSuffix(message_type)}),
+                    SharingMessageTypeToString(message_type)}),
       result);
 }
 
@@ -342,7 +345,7 @@ void LogSendSharingAckMessageResult(
   base::UmaHistogramEnumeration(metric_prefix, result);
   base::UmaHistogramEnumeration(
       base::StrCat(
-          {metric_prefix, ".", MessageTypeToMessageSuffix(message_type)}),
+          {metric_prefix, ".", SharingMessageTypeToString(message_type)}),
       result);
 
   base::UmaHistogramEnumeration(
@@ -352,7 +355,7 @@ void LogSendSharingAckMessageResult(
   base::UmaHistogramEnumeration(
       base::StrCat({metric_prefix, ".",
                     DevicePlatformToString(ack_receiver_device_type), ".",
-                    MessageTypeToMessageSuffix(message_type)}),
+                    SharingMessageTypeToString(message_type)}),
       result);
 }
 
@@ -365,7 +368,8 @@ void LogSharedClipboardRetries(int retries, SharingSendMessageResult result) {
   constexpr char kBase[] = "Sharing.SharedClipboardRetries";
   base::UmaHistogramExactLinear(kBase, retries, /*value_max=*/20);
   base::UmaHistogramExactLinear(
-      base::StrCat({kBase, ".", SendMessageResultToSuffix(result)}), retries,
+      base::StrCat({kBase, ".", SharingSendMessageResultToString(result)}),
+      retries,
       /*value_max=*/20);
 }
 

chrome/browser/sharing/sharing_metrics.h

@@ -42,9 +42,22 @@ enum class SharingDialogType {
 const char kSharingUiContextMenu[] = "ContextMenu";
 const char kSharingUiDialog[] = "Dialog";
 
+// Maps SharingSendMessageResult enums to strings used as histogram suffixes.
+// Keep in sync with "SharingSendMessageResult" in histograms.xml.
+std::string SharingSendMessageResultToString(SharingSendMessageResult result);
+
+// Maps PayloadCase enums to MessageType enums.
 chrome_browser_sharing::MessageType SharingPayloadCaseToMessageType(
     chrome_browser_sharing::SharingMessage::PayloadCase payload_case);
 
+// Maps MessageType enums to strings used as histogram suffixes. Keep in sync
+// with "SharingMessage" in histograms.xml.
+const std::string& SharingMessageTypeToString(
+    chrome_browser_sharing::MessageType message_type);
+
+// Generates trace ids for async traces in the "sharing" category.
+int GenerateSharingTraceId();
+
 // Logs the |payload_case| to UMA. This should be called when a SharingMessage
 // is received.
 void LogSharingMessageReceived(