Remove allocator_extension_thunks since this layer is not required

base/allocator/allocator_extension.h

Index: base/allocator/allocator_extension.h
diff --git a/base/allocator/allocator_extension.h b/base/allocator/allocator_extension.h
index e2f1e709fe90c0d3e8d45b09467429cb6abce020..3be2cea00c1863fc8a11f21dc29c23443a2f4709 100644
--- a/base/allocator/allocator_extension.h
+++ b/base/allocator/allocator_extension.h
@@ -7,17 +7,25 @@
 
 #include <stddef.h> // for size_t
 
-#include "base/allocator/allocator_extension_thunks.h"
 #include "base/base_export.h"
 #include "build/build_config.h"
 
 namespace base {
 namespace allocator {
 
+typedef void (*ReleaseFreeMemoryFunction)();
+typedef bool (*GetNumericPropertyFunction)(const char* name, size_t* value);
+
 // Request that the allocator release any free memory it knows about to the
 // system.
 BASE_EXPORT void ReleaseFreeMemory();
 
+// Get the named property's |value|. Returns true if the property is known.
+// Returns false if the property is not a valid property name for the current
+// allocator implementation.
+// |name| or |value| cannot be NULL
+BASE_EXPORT bool GetNumericProperty(const char* name, size_t* value);
+
 // These settings allow specifying a callback used to implement the allocator
 // extension functions.  These are optional, but if set they must only be set
 // once.  These will typically called in an allocator-specific initialization
@@ -28,10 +36,10 @@ BASE_EXPORT void ReleaseFreeMemory();
 // functions.
 
 BASE_EXPORT void SetReleaseFreeMemoryFunction(
-    thunks::ReleaseFreeMemoryFunction release_free_memory_function);
+    ReleaseFreeMemoryFunction release_free_memory_function);
 
 BASE_EXPORT void SetGetNumericPropertyFunction(
-    thunks::GetNumericPropertyFunction get_numeric_property_function);
+    GetNumericPropertyFunction get_numeric_property_function);
 
 }  // namespace allocator
 }  // namespace base