[debug] Remove dead %GetHeapUsage() runtime function.

Bug: chromium:116229
Change-Id: I16e185c2156dd7ba812f7d484c2e281febfa3635
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2606048
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Commit-Queue: Yang Guo <yangguo@chromium.org>
Auto-Submit: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#71891}

src/runtime/runtime-debug.cc

@@ -486,18 +486,6 @@ RUNTIME_FUNCTION(Runtime_CollectGarbage) {
   return ReadOnlyRoots(isolate).undefined_value();
 }
 
-
-// Gets the current heap usage.
-RUNTIME_FUNCTION(Runtime_GetHeapUsage) {
-  SealHandleScope shs(isolate);
-  DCHECK_EQ(0, args.length());
-  int usage = static_cast<int>(isolate->heap()->SizeOfObjects());
-  if (!Smi::IsValid(usage)) {
-    return *isolate->factory()->NewNumberFromInt(usage);
-  }
-  return Smi::FromInt(usage);
-}
-
 namespace {
 
 int ScriptLinePosition(Handle<Script> script, int line) {

src/runtime/runtime.h

@@ -137,7 +137,6 @@ namespace internal {
   F(GetBreakLocations, 1, 1)                    \
   F(GetGeneratorScopeCount, 1, 1)               \
   F(GetGeneratorScopeDetails, 2, 1)             \
-  F(GetHeapUsage, 0, 1)                         \
   F(HandleDebuggerStatement, 0, 1)              \
   F(IsBreakOnException, 1, 1)                   \
   F(LiveEditPatchScript, 2, 1)                  \