Set pid in SmapsPackets in memory dumps.

When pid was not set trace processor could not fill the profiler_smaps
table upid column properly.

Bug: 1098746
Change-Id: I93b4681bf9806f12835758fee8ecb66989af7b54
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2544187Reviewed-by: Eric Seckler <eseckler@chromium.org>
Reviewed-by: ssid <ssid@chromium.org>
Commit-Queue: Eric Seckler <eseckler@chromium.org>
Commit-Queue: ssid <ssid@chromium.org>
Cr-Commit-Position: refs/heads/master@{#828213}

services/resource_coordinator/public/cpp/memory_instrumentation/tracing_observer_proto.cc

@@ -120,6 +120,7 @@ bool TracingObserverProto::AddOsDumpToTraceIfEnabled(
     smaps_packet->set_timestamp_clock_id(tracing::kTraceClockId);
     perfetto::protos::pbzero::SmapsPacket* smaps =
         smaps_packet->set_smaps_packet();
+    smaps->set_pid(static_cast<uint32_t>(pid));
 
     MemoryMapsAsProtoInto(memory_maps, smaps, false);
 

services/resource_coordinator/public/cpp/memory_instrumentation/tracing_observer_proto_unittest.cc

@@ -366,8 +366,10 @@ TEST_F(TracingObserverProtoTest, AddOsDumpToTraceIfEnabled) {
   const ::perfetto::protos::SmapsPacket& smaps_packet =
       smaps_trace_packet->smaps_packet();
 
-  EXPECT_EQ(kRegionsCount, smaps_packet.entries_size());
+  EXPECT_TRUE(smaps_packet.has_pid());
+  EXPECT_EQ(static_cast<uint32_t>(kTestPid), smaps_packet.pid());
 
+  EXPECT_EQ(kRegionsCount, smaps_packet.entries_size());
   for (int i = 0; i < kRegionsCount; i++) {
     const ::perfetto::protos::SmapsEntry& entry = smaps_packet.entries(i);