Enable the allocator shim on Linux Desktop / CrOS

build/config/allocator.gni

Index: build/config/allocator.gni
diff --git a/build/config/allocator.gni b/build/config/allocator.gni
index 2c908fea6791603a79cdc4e75d2d93b9bee7a07f..c79f930b3d911e1d2eb654813f6de593d53199be 100644
--- a/build/config/allocator.gni
+++ b/build/config/allocator.gni
@@ -11,6 +11,12 @@ if (is_android || current_cpu == "mipsel" || is_mac || is_ios || is_asan ||
   _default_allocator = "tcmalloc"
 }
 
+if (is_linux && !is_asan && !is_lsan && !is_tsan && !is_msan) {
+  _default_use_experimental_allocator_shim = true
+} else {
+  _default_use_experimental_allocator_shim = false
+}
+
 declare_args() {
   # Memory allocator to use. Set to "none" to use default allocator.
   use_allocator = _default_allocator
@@ -18,7 +24,7 @@ declare_args() {
   # TODO(primiano): this should just become the default without having a flag,
   # but we need to get there first. http://crbug.com/550886 .
   # Causes all the allocations to be routed via allocator_shim.cc.
-  use_experimental_allocator_shim = false
+  use_experimental_allocator_shim = _default_use_experimental_allocator_shim
 }
 
 assert(use_allocator == "none" || use_allocator == "tcmalloc")