Fix units comparison in MemoryAllocatorDump

Calling MemoryAllocatorDump::AsProtoInto was causing a DCHECK failure.

Bug: 1098746
Change-Id: Iac11e583b7888dfe7e0b673bf47894f3ad038df8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2501481Reviewed-by: Eric Seckler <eseckler@chromium.org>
Reviewed-by: ssid <ssid@chromium.org>
Commit-Queue: Eric Seckler <eseckler@chromium.org>
Cr-Commit-Position: refs/heads/master@{#821716}

base/trace_event/memory_allocator_dump.cc

@@ -104,7 +104,7 @@ void MemoryAllocatorDump::AsProtoInto(
   for (const Entry& entry : entries_) {
     if (entry.name == "size") {
       DCHECK_EQ(entry.entry_type, Entry::EntryType::kUint64);
-      DCHECK_EQ(entry.units, "kBytes");
+      DCHECK_EQ(entry.units, kUnitsBytes);
       memory_node->set_size_bytes(entry.value_uint64);
       continue;
     }
@@ -122,11 +122,11 @@ void MemoryAllocatorDump::AsProtoInto(
         proto_memory_node_entry->set_value_string(entry.value_string);
         break;
     }
-    if (entry.units == "kBytes") {
+    if (entry.units == kUnitsBytes) {
       proto_memory_node_entry->set_units(
           perfetto::protos::pbzero::MemoryTrackerSnapshot::ProcessSnapshot::
               MemoryNode::MemoryNodeEntry::BYTES);
-    } else if (entry.units == "kObjects") {
+    } else if (entry.units == kUnitsObjects) {
       proto_memory_node_entry->set_units(
           perfetto::protos::pbzero::MemoryTrackerSnapshot::ProcessSnapshot::
               MemoryNode::MemoryNodeEntry::COUNT);

services/resource_coordinator/public/cpp/memory_instrumentation/tracing_observer_proto_unittest.cc

@@ -371,11 +371,13 @@ TEST_F(TracingObserverProtoTest, AsProtoInto) {
   base::trace_event::ProcessMemoryDump pmd =
       base::trace_event::ProcessMemoryDump(dump_args);
 
-  base::trace_event::MemoryAllocatorDump* dump = pmd.CreateAllocatorDump(
+  using MemoryAllocatorDump = base::trace_event::MemoryAllocatorDump;
+
+  MemoryAllocatorDump* dump = pmd.CreateAllocatorDump(
       "mad1", base::trace_event::MemoryAllocatorDumpGuid(421));
-  dump->AddScalar("size", "kBytes", 10);
-  dump->AddScalar("one", "kBytes", 1);
-  dump->AddString("two", "kObjects", "one");
+  dump->AddScalar("size", MemoryAllocatorDump::kUnitsBytes, 10);
+  dump->AddScalar("one", MemoryAllocatorDump::kUnitsBytes, 1);
+  dump->AddString("two", MemoryAllocatorDump::kUnitsObjects, "one");
 
   perfetto::TraceWriter::TracePacketHandle handle =
       trace_writer->NewTracePacket();