Post the build tool logs event from the BuildTool

Collect the relevant data in the BuildResult and post the build tool
logs event from a central location rather than a module. Maybe not the
ideal location, but we have multiple modules that need to contribute
to build tool logs, so it must be posted from a common location. It
could be in a module, except that would require modules depending on /
extending other modules, which we don't support right now.

Note that this change includes a fix to LastBuildEvent, without which
this wouldn't work since this change is changing the order of the last
two events posted.

PiperOrigin-RevId: 222061608
diff --git a/src/main/java/com/google/devtools/build/lib/runtime/BuildSummaryStatsModule.java b/src/main/java/com/google/devtools/build/lib/runtime/BuildSummaryStatsModule.java
index 9f237d4..5b10cf0 100644
--- a/src/main/java/com/google/devtools/build/lib/runtime/BuildSummaryStatsModule.java
+++ b/src/main/java/com/google/devtools/build/lib/runtime/BuildSummaryStatsModule.java
@@ -14,13 +14,11 @@
 package com.google.devtools.build.lib.runtime;
 
 import com.google.common.base.Joiner;
-import com.google.common.collect.ImmutableList;
 import com.google.common.eventbus.AllowConcurrentEvents;
 import com.google.common.eventbus.EventBus;
 import com.google.common.eventbus.Subscribe;
 import com.google.devtools.build.lib.actions.ActionKeyContext;
 import com.google.devtools.build.lib.actions.ActionResultReceivedEvent;
-import com.google.devtools.build.lib.buildeventstream.BuildToolLogs;
 import com.google.devtools.build.lib.buildtool.BuildRequest;
 import com.google.devtools.build.lib.buildtool.buildevent.BuildCompleteEvent;
 import com.google.devtools.build.lib.buildtool.buildevent.ExecutionStartingEvent;
@@ -32,8 +30,7 @@
 import com.google.devtools.build.lib.profiler.Profiler;
 import com.google.devtools.build.lib.profiler.ProfilerTask;
 import com.google.devtools.build.lib.profiler.SilentCloseable;
-import com.google.devtools.build.lib.util.Pair;
-import com.google.protobuf.ByteString;
+import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.logging.Logger;
@@ -93,11 +90,13 @@
   public void buildComplete(BuildCompleteEvent event) {
     try {
       // We might want to make this conditional on a flag; it can sometimes be a bit of a nuisance.
-      List<Pair<String, ByteString>> statistics = new ArrayList<>();
       List<String> items = new ArrayList<>();
       items.add(String.format("Elapsed time: %.3fs", event.getResult().getElapsedSeconds()));
-      statistics.add(Pair.of("elapsed time", ByteString.copyFromUtf8(
-          String.format("%f", event.getResult().getElapsedSeconds()))));
+      event.getResult().getBuildToolLogCollection()
+          .addDirectValue(
+              "elapsed time",
+              String.format(
+                  "%f", event.getResult().getElapsedSeconds()).getBytes(StandardCharsets.UTF_8));
 
       if (criticalPathComputer != null) {
         try (SilentCloseable c =
@@ -105,8 +104,9 @@
           AggregatedCriticalPath criticalPath =
               criticalPathComputer.aggregate();
           items.add(criticalPath.toStringSummaryNoRemote());
-          statistics.add(
-              Pair.of("critical path", ByteString.copyFromUtf8(criticalPath.toString())));
+          event.getResult().getBuildToolLogCollection()
+              .addDirectValue(
+                  "critical path", criticalPath.toString().getBytes(StandardCharsets.UTF_8));
           logger.info(criticalPath.toString());
           logger.info(
               "Slowest actions:\n  "
@@ -129,9 +129,9 @@
 
       String spawnSummary = spawnStats.getSummary();
       reporter.handle(Event.info(spawnSummary));
-      statistics.add(Pair.of("process stats", ByteString.copyFromUtf8(spawnSummary)));
 
-      reporter.post(new BuildToolLogs(statistics, ImmutableList.of(), ImmutableList.of()));
+      event.getResult().getBuildToolLogCollection()
+          .addDirectValue("process stats", spawnSummary.getBytes(StandardCharsets.UTF_8));
     } finally {
       criticalPathComputer = null;
     }