musl does not implement mallinfo()/mallinfo2()
(or rather, malloc-ng, musl's allocator, doesn't)
--
--- a/src/3rdparty/chromium/base/trace_event/malloc_dump_provider.cc
+++ b/src/3rdparty/chromium/base/trace_event/malloc_dump_provider.cc
@@ -185,7 +185,6 @@
 #define MALLINFO2_FOUND_IN_LIBC
   struct mallinfo2 info = mallinfo2();
 #endif
-#endif  // defined(__GLIBC__) && defined(__GLIBC_PREREQ)
 #if !defined(MALLINFO2_FOUND_IN_LIBC)
   struct mallinfo info = mallinfo();
 #endif
@@ -205,6 +204,7 @@
     sys_alloc_dump->AddScalar(MemoryAllocatorDump::kNameSize,
                               MemoryAllocatorDump::kUnitsBytes, info.uordblks);
   }
+#endif  // defined(__GLIBC__) && defined(__GLIBC_PREREQ)
 }
 #endif
 
@@ -339,7 +340,7 @@
                      &allocated_objects_count);
 #elif BUILDFLAG(IS_FUCHSIA)
 // TODO(fuchsia): Port, see https://crbug.com/706592.
-#else
+#elif defined(__GLIBC__)
   ReportMallinfoStats(/*pmd=*/nullptr, &total_virtual_size, &resident_size,
                       &allocated_objects_size, &allocated_objects_count);
 #endif
--- a/src/3rdparty/chromium/base/process/process_metrics_posix.cc
+++ b/src/3rdparty/chromium/base/process/process_metrics_posix.cc
@@ -105,7 +105,7 @@
 
 #endif  // !BUILDFLAG(IS_FUCHSIA)
 
-#if BUILDFLAG(IS_LINUX) || BUILDFLAG(IS_CHROMEOS) || BUILDFLAG(IS_ANDROID)
+#if (BUILDFLAG(IS_LINUX) && defined(__GLIBC__)) || BUILDFLAG(IS_CHROMEOS) || BUILDFLAG(IS_ANDROID)
 namespace {
 
 size_t GetMallocUsageMallinfo() {
@@ -123,7 +123,7 @@
 }
 
 }  // namespace
-#endif  // BUILDFLAG(IS_LINUX) || BUILDFLAG(IS_CHROMEOS) ||
+#endif  // (BUILDFLAG(IS_LINUX) && defined(__GLIBC__)) || BUILDFLAG(IS_CHROMEOS) ||
         // BUILDFLAG(IS_ANDROID)
 
 size_t ProcessMetrics::GetMallocUsage() {
@@ -131,9 +131,9 @@
   malloc_statistics_t stats = {0};
   malloc_zone_statistics(nullptr, &stats);
   return stats.size_in_use;
-#elif BUILDFLAG(IS_LINUX) || BUILDFLAG(IS_CHROMEOS) || BUILDFLAG(IS_ANDROID)
+#elif (BUILDFLAG(IS_LINUX) && defined(__GLIBC__)) || BUILDFLAG(IS_CHROMEOS) || BUILDFLAG(IS_ANDROID)
   return GetMallocUsageMallinfo();
-#elif BUILDFLAG(IS_FUCHSIA)
+#else
   // TODO(fuchsia): Not currently exposed. https://crbug.com/735087.
   return 0;
 #endif