Change UMA logging to only log once for same kind of error

`FullScreenPowerPointHandler::FindEditorWindow()` was previously
recording `FullScreenFindEditorResult` UMA metrics on every frame. This
causes log spam, especially when the heuristic fails due to multiple
editors having the same title.

This CL caches the previous result in `previous_find_editor_result_` and
only records the metric when the result differs from the previous call.

Bug: chromium:409473386
Change-Id: I44500864c89dd7415327c91778086ecd667cdd15
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/458041
Reviewed-by: Ilya Nikolaevskiy <ilnik@webrtc.org>
Commit-Queue: Palak Agarwal <agpalak@google.com>
Cr-Commit-Position: refs/heads/main@{#47193}

modules/desktop_capture/win/full_screen_win_application_handler.cc

diff --git a/modules/desktop_capture/win/full_screen_win_application_handler.cc b/modules/desktop_capture/win/full_screen_win_application_handler.cc
index c7548b0..7a245c9 100644
--- a/modules/desktop_capture/win/full_screen_win_application_handler.cc
+++ b/modules/desktop_capture/win/full_screen_win_application_handler.cc
@@ -36,10 +36,16 @@
       static_cast<int>(FullScreenDetectorResult::kMaxValue));
 }
 
-void RecordFullScreenFindEditorResult(FullScreenFindEditorResult result) {
-  RTC_HISTOGRAM_ENUMERATION(
-      "WebRTC.Screenshare.FullScreenFindEditorResult", static_cast<int>(result),
-      static_cast<int>(FullScreenFindEditorResult::kMaxValue));
+void MaybeRecordFullScreenFindEditorResult(
+    FullScreenFindEditorResult result,
+    std::optional<FullScreenFindEditorResult>& previous_result) {
+  if (previous_result != result) {
+    RTC_HISTOGRAM_ENUMERATION(
+        "WebRTC.Screenshare.FullScreenFindEditorResult",
+        static_cast<int>(result),
+        static_cast<int>(FullScreenFindEditorResult::kMaxValue));
+    previous_result = result;
+  }
 }
 
 namespace webrtc {
@@ -246,15 +252,17 @@
   }
 
   if (editor_ids.size() != 1) {
-    RecordFullScreenFindEditorResult(
-        FullScreenFindEditorResult::kFailureDueToSameTitleWindows);
+    MaybeRecordFullScreenFindEditorResult(
+        FullScreenFindEditorResult::kFailureDueToSameTitleWindows,
+        previous_find_editor_result_);
     // If `editor_ids` has more than one id, then there are multiple open
     // editors with the same title as the full screen slide show and then
     // there's no way of knowing which editor has opened the slide show.
     return 0;
   }
 
-  RecordFullScreenFindEditorResult(FullScreenFindEditorResult::kSuccess);
+  MaybeRecordFullScreenFindEditorResult(FullScreenFindEditorResult::kSuccess,
+                                        previous_find_editor_result_);
   return *editor_ids.begin();
 }
 

modules/desktop_capture/win/full_screen_win_application_handler.h

diff --git a/modules/desktop_capture/win/full_screen_win_application_handler.h b/modules/desktop_capture/win/full_screen_win_application_handler.h
index 0accd62..3a51cea 100644
--- a/modules/desktop_capture/win/full_screen_win_application_handler.h
+++ b/modules/desktop_capture/win/full_screen_win_application_handler.h
@@ -15,6 +15,7 @@
 
 #include <cstdint>
 #include <memory>
+#include <optional>
 #include <string>
 
 #include "modules/desktop_capture/desktop_capturer.h"
@@ -82,6 +83,9 @@
   mutable bool was_slide_show_created_after_capture_started_;
 
   mutable FullScreenDetectorResult full_screen_detector_result_;
+
+  mutable std::optional<FullScreenFindEditorResult>
+      previous_find_editor_result_;
 };
 
 std::unique_ptr<FullScreenApplicationHandler>