Fold most logic from //base/allocator into //base.

base/BUILD.gn

Index: base/BUILD.gn
diff --git a/base/BUILD.gn b/base/BUILD.gn
index 7f46e71ae532ed8af7a7c9dfd6873e86672a0a25..69dfcc5b3bbe28700b259a9ad2e2decec8e70b4c 100644
--- a/base/BUILD.gn
+++ b/base/BUILD.gn
@@ -1083,6 +1083,7 @@ component("base") {
     "win/wrapped_window_proc.h",
   ]
 
+  all_dependent_configs = []
   defines = []
   data = []
 
@@ -1113,9 +1114,37 @@ component("base") {
   }
 
   if (use_experimental_allocator_shim) {
-    # The allocator shim is part of the base API. This is to allow clients of
-    # base should to install hooks into the allocator path.
-    public_deps += [ "//base/allocator:unified_allocator_shim" ]
+    # TODO(primiano): support other platforms, currently this works only on
+    # Linux/CrOS/Android. http://crbug.com/550886 .
+    sources += [
+      "allocator/allocator_shim.cc",
+      "allocator/allocator_shim.h",
+      "allocator/allocator_shim_internals.h",
+      "allocator/allocator_shim_override_cpp_symbols.h",
+      "allocator/allocator_shim_override_libc_symbols.h",
+    ]
+    if (is_win) {
+      sources += [
+        "allocator/allocator_shim_default_dispatch_to_winheap.cc",
+        "allocator/allocator_shim_override_ucrt_symbols_win.h",
+        "allocator/winheap_stubs_win.cc",
+        "allocator/winheap_stubs_win.h",
+      ]
+    } else if (is_linux && use_allocator == "tcmalloc") {
+      sources += [
+        "allocator/allocator_shim_default_dispatch_to_tcmalloc.cc",
+        "allocator/allocator_shim_override_glibc_weak_symbols.h",
+      ]
+      deps += [ "//base/allocator:tcmalloc" ]
+    } else if (is_linux && use_allocator == "none") {
+      sources += [ "allocator/allocator_shim_default_dispatch_to_glibc.cc" ]
+    } else if (is_android && use_allocator == "none") {
+      sources += [
+        "allocator/allocator_shim_default_dispatch_to_linker_wrapped_symbols.cc",
+        "allocator/allocator_shim_override_linker_wrapped_symbols.h",
+      ]
+      all_dependent_configs += [ "//base/allocator:wrap_malloc_symbols" ]
+    }
   }
 
   # Allow more direct string conversions on platforms with native utf8
@@ -1376,7 +1405,7 @@ component("base") {
       "userenv.lib",
       "winmm.lib",
     ]
-    all_dependent_configs = [ ":base_win_linker_flags" ]
+    all_dependent_configs += [ ":base_win_linker_flags" ]
   } else if (!is_nacl || is_nacl_nonsfi) {
     # Non-Windows.
     deps += [ "//base/third_party/libevent" ]
@@ -1433,7 +1462,7 @@ component("base") {
     defines += [ "USE_SYMBOLIZE" ]
 
     configs += linux_configs
-    all_dependent_configs = linux_configs
+    all_dependent_configs += linux_configs
 
     # These dependencies are not required on Android, and in the case
     # of xdg_mime must be excluded due to licensing restrictions.