Perfetto: Move in-process mode behind a feature flag while investigating crash

R=ssid@chromium.org
BUG=961609

Change-Id: Ic25d4eb36f90506c8d21abf3df35fb3f11474746
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1616447
Commit-Queue: oysteine <oysteine@chromium.org>
Reviewed-by: ssid <ssid@chromium.org>
Cr-Commit-Position: refs/heads/master@{#660715}

services/tracing/perfetto/producer_host.cc

@@ -11,6 +11,7 @@
 #include "services/tracing/perfetto/perfetto_service.h"
 #include "services/tracing/public/cpp/perfetto/producer_client.h"
 #include "services/tracing/public/cpp/perfetto/shared_memory.h"
+#include "services/tracing/public/cpp/tracing_features.h"
 #include "third_party/perfetto/include/perfetto/tracing/core/commit_data_request.h"
 #include "third_party/perfetto/include/perfetto/tracing/core/data_source_descriptor.h"
 #include "third_party/perfetto/include/perfetto/tracing/core/trace_config.h"
@@ -46,9 +47,12 @@ void ProducerHost::Initialize(mojom::ProducerClientPtr producer_client,
   //   hence we avoid any deadlocking occurring from trace events emitted from
   //   the Perfetto sequence filling up the SMB and stalling while waiting for
   //   Perfetto to free the chunks.
-  base::ProcessId pid;
-  if (PerfettoService::ParsePidFromProducerName(name, &pid)) {
-    is_in_process_ = (pid == base::Process::Current().Pid());
+  if (!base::FeatureList::IsEnabled(
+          features::kPerfettoForceOutOfProcessProducer)) {
+    base::ProcessId pid;
+    if (PerfettoService::ParsePidFromProducerName(name, &pid)) {
+      is_in_process_ = (pid == base::Process::Current().Pid());
+    }
   }
 
   // TODO(oysteine): Figure out an uid once we need it.

services/tracing/public/cpp/tracing_features.cc

@@ -24,6 +24,10 @@ const base::Feature kTracingPerfettoBackend{"TracingPerfettoBackend",
 const base::Feature kBackgroundTracingProtoOutput{
     "BackgroundTracingProtoOutput", base::FEATURE_DISABLED_BY_DEFAULT};
 
+// Causes Perfetto to run in-process mode for in-process tracing producers.
+const base::Feature kPerfettoForceOutOfProcessProducer{
+    "PerfettoForceOutOfProcessProducer", base::FEATURE_ENABLED_BY_DEFAULT};
+
 // Runs the tracing service as an in-process browser service.
 const base::Feature kTracingServiceInProcess {
   "TracingServiceInProcess",

services/tracing/public/cpp/tracing_features.h

@@ -24,6 +24,9 @@ extern const COMPONENT_EXPORT(TRACING_CPP) base::Feature
 extern const COMPONENT_EXPORT(TRACING_CPP) base::Feature
     kBackgroundTracingProtoOutput;
 
+extern const COMPONENT_EXPORT(TRACING_CPP) base::Feature
+    kPerfettoForceOutOfProcessProducer;
+
 }  // namespace features
 
 namespace tracing {