tcmalloc: compile heap profiler code only when explicitly requested

Conditionally compile the heap profiler code and its dependencies when
enable_profiling is set to true.
This removes 9 static initializers in memory_region_map.cc with the new
tcmalloc in release builds.

BUG=b:119055819
TEST=Unit tests pass

Change-Id: I99adbf662d97f40304e698661506ad0d2c066d79
Reviewed-on: https://chromium-review.googlesource.com/c/1464324
Commit-Queue: Gabriel Marin <gmx@chromium.org>
Reviewed-by: Will Harris <wfh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#636570}

base/allocator/BUILD.gn

@@ -143,9 +143,6 @@ if (use_allocator == "tcmalloc") {
       "$tcmalloc_dir/src/gperftools/malloc_extension.h",
       "$tcmalloc_dir/src/gperftools/malloc_hook.h",
       "$tcmalloc_dir/src/gperftools/stacktrace.h",
-      "$tcmalloc_dir/src/heap-profile-table.cc",
-      "$tcmalloc_dir/src/heap-profile-table.h",
-      "$tcmalloc_dir/src/heap-profiler.cc",
       "$tcmalloc_dir/src/internal_logging.cc",
       "$tcmalloc_dir/src/internal_logging.h",
       "$tcmalloc_dir/src/linked_list.h",
@@ -154,8 +151,6 @@ if (use_allocator == "tcmalloc") {
       "$tcmalloc_dir/src/malloc_hook.cc",
       "$tcmalloc_dir/src/maybe_threads.cc",
       "$tcmalloc_dir/src/maybe_threads.h",
-      "$tcmalloc_dir/src/memory_region_map.cc",
-      "$tcmalloc_dir/src/memory_region_map.h",
       "$tcmalloc_dir/src/page_heap.cc",
       "$tcmalloc_dir/src/page_heap.h",
       "$tcmalloc_dir/src/raw_printer.cc",
@@ -238,6 +233,11 @@ if (use_allocator == "tcmalloc") {
       sources += [
         "$tcmalloc_dir/src/base/thread_lister.c",
         "$tcmalloc_dir/src/base/thread_lister.h",
+        "$tcmalloc_dir/src/heap-profile-table.cc",
+        "$tcmalloc_dir/src/heap-profile-table.h",
+        "$tcmalloc_dir/src/heap-profiler.cc",
+        "$tcmalloc_dir/src/memory_region_map.cc",
+        "$tcmalloc_dir/src/memory_region_map.h",
         "$tcmalloc_dir/src/profile-handler.cc",
         "$tcmalloc_dir/src/profile-handler.h",
         "$tcmalloc_dir/src/profiledata.cc",

base/allocator/allocator_extension.cc

@@ -48,7 +48,7 @@ void GetHeapSample(std::string* writer) {
 }
 
 bool IsHeapProfilerRunning() {
-#if defined(USE_TCMALLOC)
+#if defined(USE_TCMALLOC) && defined(ENABLE_PROFILING)
   return ::IsHeapProfilerRunning();
 #endif
   return false;