[cpu-profiler] Fix a leak caused by re-logging existing functions.

Don't re-log all existing functions during StartProcessorIfNotStarted().
They will already be in the CodeMap attached to the ProfileGenerator and
re-logging them causes leaks. See the linked bug for more details.

Bug: v8:8253
Change-Id: Ibb1a1ab2431c588e8c3a3a9ff714767cdf61a88e
Reviewed-on: https://chromium-review.googlesource.com/1256763
Commit-Queue: Peter Marshall <petermarshall@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56336}

src/profiler/cpu-profiler.cc

@@ -368,8 +368,11 @@ void CpuProfiler::StartProcessorIfNotStarted() {
   // Disable logging when using the new implementation.
   saved_is_logging_ = logger->is_logging_;
   logger->is_logging_ = false;
+
+  bool codemap_needs_initialization = false;
   if (!generator_) {
     generator_.reset(new ProfileGenerator(profiles_.get()));
+    codemap_needs_initialization = true;
     CreateEntriesForRuntimeCallStats();
   }
   processor_.reset(new ProfilerEventsProcessor(isolate_, generator_.get(),
@@ -382,12 +385,14 @@ void CpuProfiler::StartProcessorIfNotStarted() {
   isolate_->set_is_profiling(true);
   // Enumerate stuff we already have in the heap.
   DCHECK(isolate_->heap()->HasBeenSetUp());
-  if (!FLAG_prof_browser_mode) {
-    logger->LogCodeObjects();
+  if (codemap_needs_initialization) {
+    if (!FLAG_prof_browser_mode) {
+      logger->LogCodeObjects();
+    }
+    logger->LogCompiledFunctions();
+    logger->LogAccessorCallbacks();
+    LogBuiltins();
   }
-  logger->LogCompiledFunctions();
-  logger->LogAccessorCallbacks();
-  LogBuiltins();
   // Enable stack sampling.
   processor_->AddCurrentStack(isolate_);
   processor_->StartSynchronously();