Revert of SkVarAlloc::approxBytesAllocated

src/core/SkVarAlloc.cpp

Index: src/core/SkVarAlloc.cpp
diff --git a/src/core/SkVarAlloc.cpp b/src/core/SkVarAlloc.cpp
index 8f84b95743e5ba54d80b39ec34c0c7c2b4f1c502..6f5b5a18d3a16427a9d6c7b49bfb1bbfa1f53b24 100644
--- a/src/core/SkVarAlloc.cpp
+++ b/src/core/SkVarAlloc.cpp
@@ -3,7 +3,7 @@
 // We use non-standard malloc diagnostic methods to make sure our allocations are sized well.
 #if defined(SK_BUILD_FOR_MAC)
     #include <malloc/malloc.h>
-#elif defined(SK_BUILD_FOR_UNIX) || defined(SK_BUILD_FOR_WIN32)
+#elif defined(SK_BUILD_FOR_LINUX)
     #include <malloc.h>
 #endif
 
@@ -56,28 +56,7 @@
 
 #if defined(SK_BUILD_FOR_MAC)
     SkASSERT(alloc == malloc_good_size(alloc));
-#elif defined(SK_BUILD_FOR_UNIX)
-    // TODO(mtklein): tune so we can assert something like this
-    //SkASSERT(alloc == malloc_usable_size(fBlock));
+#elif defined(SK_BUILD_FOR_LINUX)
+    SkASSERT(alloc == malloc_usable_size(fByte - sizeof(Block)));
 #endif
 }
-
-static size_t heap_size(void* p) {
-#if defined(SK_BUILD_FOR_MAC)
-    return malloc_size(p);
-#elif defined(SK_BUILD_FOR_UNIX)
-    return malloc_usable_size(p);
-#elif defined(SK_BUILD_FOR_WIN32)
-    return _msize(p);
-#else
-    return 0;  // Tough luck.
-#endif
-}
-
-size_t SkVarAlloc::approxBytesAllocated() const {
-    size_t sum = 0;
-    for (Block* b = fBlock; b; b = b->prev) {
-        sum += heap_size(b);
-    }
-    return sum;
-}