Stop comparing Descriptions with memcmp

bug:27894959
Change-Id: I379c11381c08f6f77577a914638b32415768f26e
diff --git a/libs/hwui/utils/Macros.h b/libs/hwui/utils/Macros.h
index ccf2287..7212897b 100644
--- a/libs/hwui/utils/Macros.h
+++ b/libs/hwui/utils/Macros.h
@@ -23,12 +23,10 @@
         Type(const Type&) = delete; \
         void operator=(const Type&) = delete
 
-#define DESCRIPTION_TYPE(Type) \
-        int compare(const Type& rhs) const { return memcmp(this, &rhs, sizeof(Type));} \
-        bool operator==(const Type& other) const { return compare(other) == 0; } \
-        bool operator!=(const Type& other) const { return compare(other) != 0; } \
-        friend inline int strictly_order_type(const Type& lhs, const Type& rhs) { return lhs.compare(rhs) < 0; } \
-        friend inline int compare_type(const Type& lhs, const Type& rhs) { return lhs.compare(rhs); } \
+#define HASHABLE_TYPE(Type) \
+        bool operator==(const Type& other) const; \
+        hash_t hash() const; \
+        bool operator!=(const Type& other) const { return !(*this == other); } \
         friend inline hash_t hash_type(const Type& entry) { return entry.hash(); }
 
 #define REQUIRE_COMPATIBLE_LAYOUT(Type) \