Frame screenshot event generation

Summary:
Adds CDP event generation for screenshots.

Changelog: [Internal]

Differential Revision: D87936872

Author: sbuggay

packages/react-native/ReactCommon/jsinspector-modern/tracing/HostTracingProfileSerializer.cpp

@@ -121,6 +121,19 @@ constexpr int FALLBACK_LAYER_TREE_ID = 1;
     chunk.push_back(TraceEventSerializer::serialize(std::move(commitEvent)));
     chunk.push_back(
         TraceEventSerializer::serialize(std::move(endDrawingEvent)));
+
+    if (frameTimingSequence.screenshot.has_value()) {
+      auto screenshotEvent = TraceEventGenerator::createScreenshotEvent(
+          frameTimingSequence.id,
+          FALLBACK_LAYER_TREE_ID,
+          std::move(frameTimingSequence.screenshot.value()),
+          frameTimingSequence.endDrawingTimestamp,
+          processId,
+          frameTimingSequence.threadId);
+
+      chunk.push_back(
+          TraceEventSerializer::serialize(std::move(screenshotEvent)));
+    }
   }
 
   if (!chunk.empty()) {

packages/react-native/ReactCommon/jsinspector-modern/tracing/TraceEventGenerator.cpp

@@ -6,6 +6,7 @@
  */
 
 #include "TraceEventGenerator.h"
+#include "Timing.h"
 #include "TracingCategory.h"
 
 namespace facebook::react::jsinspector_modern::tracing {
@@ -77,4 +78,27 @@ TraceEventGenerator::createFrameTimingsEvents(
   return {std::move(beginEvent), std::move(commitEvent), std::move(drawEvent)};
 }
 
+/* static */ TraceEvent TraceEventGenerator::createScreenshotEvent(
+    uint64_t frameSequence,
+    int sourceId,
+    std::string snapshot,
+    HighResTimeStamp expectedDisplayTime,
+    ProcessId processId,
+    ThreadId threadId) {
+  folly::dynamic data = folly::dynamic::object("snapshot", std::move(snapshot))(
+      "source_id", sourceId)("frame_sequence", frameSequence)(
+      "expected_display_time",
+      highResTimeStampToTracingClockTimeStamp(expectedDisplayTime));
+
+  return TraceEvent{
+      .name = "Screenshot",
+      .cat = {Category::Screenshot},
+      .ph = 'O',
+      .ts = expectedDisplayTime,
+      .pid = processId,
+      .tid = threadId,
+      .args = std::move(data),
+  };
+}
+
 }; // namespace facebook::react::jsinspector_modern::tracing

packages/react-native/ReactCommon/jsinspector-modern/tracing/TraceEventGenerator.h

@@ -42,6 +42,17 @@ class TraceEventGenerator {
       HighResTimeStamp endDrawingTimestamp,
       ProcessId processId,
       ThreadId threadId);
+
+  /**
+   * Creates canonical "Screenshot" trace event.
+   */
+  static TraceEvent createScreenshotEvent(
+      uint64_t frameSequence,
+      int sourceId,
+      std::string snapshot,
+      HighResTimeStamp expectedDisplayTime,
+      ProcessId processId,
+      ThreadId threadId);
 };
 
 }; // namespace facebook::react::jsinspector_modern::tracing