[heap] Reland uncommit unused large object page memory.

src/base/platform/platform-win32.cc

Index: src/base/platform/platform-win32.cc
diff --git a/src/base/platform/platform-win32.cc b/src/base/platform/platform-win32.cc
index 0076a35ce502e53a1b1c0b10251ad0cd59130046..d4c2a10bd697cab501f9db460606af22c730b30f 100644
--- a/src/base/platform/platform-win32.cc
+++ b/src/base/platform/platform-win32.cc
@@ -1290,6 +1290,10 @@ bool VirtualMemory::UncommitRegion(void* base, size_t size) {
   return VirtualFree(base, size, MEM_DECOMMIT) != 0;
 }
 
+bool VirtualMemory::ReleasePartialRegion(void* base, size_t size,
+                                         void* free_start, size_t free_size) {
+  return VirtualFree(free_start, free_size, MEM_DECOMMIT) != 0;
+}
 
 bool VirtualMemory::ReleaseRegion(void* base, size_t size) {
   return VirtualFree(base, 0, MEM_RELEASE) != 0;