Introduce allocator shim for Android

base/allocator/BUILD.gn

Index: base/allocator/BUILD.gn
diff --git a/base/allocator/BUILD.gn b/base/allocator/BUILD.gn
index c1599bb6855669c1a2d39fe2b038f0918e5c42f5..b2ec91e40c5842a6bcee91dea4dd03824a150653 100644
--- a/base/allocator/BUILD.gn
+++ b/base/allocator/BUILD.gn
@@ -267,9 +267,23 @@ buildflag_header("features") {
 }
 
 if (use_experimental_allocator_shim) {
+  # Used to shim malloc symbols on Android. see //base/allocator/README.md.
+  config("wrap_malloc_symbols") {
+    ldflags = [
+      "-Wl,-wrap,calloc",
+      "-Wl,-wrap,free",
+      "-Wl,-wrap,malloc",
+      "-Wl,-wrap,memalign",
+      "-Wl,-wrap,posix_memalign",
+      "-Wl,-wrap,pvalloc",
+      "-Wl,-wrap,realloc",
+      "-Wl,-wrap,valloc",
+    ]
+  }
+
   source_set("unified_allocator_shim") {
     # TODO(primiano): support other platforms, currently this works only on
-    # Linux/CrOS. http://crbug.com/550886 .
+    # Linux/CrOS/Android. http://crbug.com/550886 .
     configs += [ "//base:base_implementation" ]  # for BASE_EXPORT
     visibility = [ "//base:base" ]
     sources = [
@@ -289,6 +303,12 @@ if (use_experimental_allocator_shim) {
       ]
     } else if (is_linux && use_allocator == "none") {
       sources += [ "allocator_shim_default_dispatch_to_glibc.cc" ]
+    } else if (is_android && use_allocator == "none") {
+      sources += [
+        "allocator_shim_default_dispatch_to_linker_wrapped_symbols.cc",
+        "allocator_shim_override_linker_wrapped_symbols.h",
+      ]
+      all_dependent_configs = [ ":wrap_malloc_symbols" ]
     }
   }
 }