Add flags and skeleton for profiling process.

chrome/common/features.gni

Index: chrome/common/features.gni
diff --git a/chrome/common/features.gni b/chrome/common/features.gni
index 760668f6578e3824846190dee5b501e20469aea2..de9a2fc393f3328f4b9ee6e7304f4677536821f1 100644
--- a/chrome/common/features.gni
+++ b/chrome/common/features.gni
@@ -53,6 +53,10 @@ declare_args() {
   # /device/gamepad as backend.
   enable_exo_ozone_gamepad = use_ozone
 
+  # Enable out-of-process logging of heap profiling data. Currently being
+  # implemented.
+  enable_oop_heap_profiling = false
+
   # Set to true to bundle all the mash related mojo services into chrome.
   # Specify --mash to chrome to have chrome start the mash environment.
   enable_package_mash_services = is_chromeos