Emit trace event on console error messages from JS.

This is needed to implement a new metric that measures
health of Web Page Replay archives.

Bug: chromium:880432

Cq-Include-Trybots: luci.chromium.try:linux_chromium_headless_rel;master.tryserver.blink:linux_trusty_blink_rel
Change-Id: I59aed22e4671e491fc3a30d04fbdce1643404b32
Reviewed-on: https://chromium-review.googlesource.com/1204570
Commit-Queue: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Pavel Feldman <pfeldman@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#55716}

src/inspector/v8-console-message.cc

@@ -13,6 +13,7 @@
 #include "src/inspector/v8-inspector-session-impl.h"
 #include "src/inspector/v8-runtime-agent-impl.h"
 #include "src/inspector/v8-stack-trace-impl.h"
+#include "src/tracing/trace-event.h"
 
 #include "include/v8-inspector.h"
 
@@ -477,12 +478,34 @@ V8ConsoleMessageStorage::V8ConsoleMessageStorage(V8InspectorImpl* inspector,
 
 V8ConsoleMessageStorage::~V8ConsoleMessageStorage() { clear(); }
 
+namespace {
+
+void TraceV8ConsoleMessageEvent(V8MessageOrigin origin, ConsoleAPIType type) {
+  // Change in this function requires adjustment of Catapult/Telemetry metric
+  // tracing/tracing/metrics/console_error_metric.html.
+  // See https://crbug.com/880432
+  if (origin == V8MessageOrigin::kException) {
+    TRACE_EVENT_INSTANT0("v8.console", "V8ConsoleMessage::Exception",
+                         TRACE_EVENT_SCOPE_THREAD);
+  } else if (type == ConsoleAPIType::kError) {
+    TRACE_EVENT_INSTANT0("v8.console", "V8ConsoleMessage::Error",
+                         TRACE_EVENT_SCOPE_THREAD);
+  } else if (type == ConsoleAPIType::kAssert) {
+    TRACE_EVENT_INSTANT0("v8.console", "V8ConsoleMessage::Assert",
+                         TRACE_EVENT_SCOPE_THREAD);
+  }
+}
+
+}  // anonymous namespace
+
 void V8ConsoleMessageStorage::addMessage(
     std::unique_ptr<V8ConsoleMessage> message) {
   int contextGroupId = m_contextGroupId;
   V8InspectorImpl* inspector = m_inspector;
   if (message->type() == ConsoleAPIType::kClear) clear();
 
+  TraceV8ConsoleMessageEvent(message->origin(), message->type());
+
   inspector->forEachSession(
       contextGroupId, [&message](V8InspectorSessionImpl* session) {
         if (message->origin() == V8MessageOrigin::kConsole)