Revert of Fix free memory calculation.

base/process/process_metrics_linux.cc

Index: base/process/process_metrics_linux.cc
diff --git a/base/process/process_metrics_linux.cc b/base/process/process_metrics_linux.cc
index 114deda49e390bc73b13e68a5aa6abdbb09f6ccb..b14aa210bd57af5bd53c6581590fa221f355d9bb 100644
--- a/base/process/process_metrics_linux.cc
+++ b/base/process/process_metrics_linux.cc
@@ -532,12 +532,45 @@
 
 }  // namespace
 
+SystemMemoryInfoKB::SystemMemoryInfoKB() {
+  total = 0;
+  free = 0;
+#if defined(OS_LINUX)
+  available = 0;
+#endif
+  buffers = 0;
+  cached = 0;
+  active_anon = 0;
+  inactive_anon = 0;
+  active_file = 0;
+  inactive_file = 0;
+  swap_total = 0;
+  swap_free = 0;
+  dirty = 0;
+
+  pswpin = 0;
+  pswpout = 0;
+  pgmajfault = 0;
+
+#ifdef OS_CHROMEOS
+  shmem = 0;
+  slab = 0;
+  gem_objects = -1;
+  gem_size = -1;
+#endif
+}
+
+SystemMemoryInfoKB::SystemMemoryInfoKB(const SystemMemoryInfoKB& other) =
+    default;
+
 std::unique_ptr<Value> SystemMemoryInfoKB::ToValue() const {
   std::unique_ptr<DictionaryValue> res(new DictionaryValue());
 
   res->SetInteger("total", total);
   res->SetInteger("free", free);
+#if defined(OS_LINUX)
   res->SetInteger("available", available);
+#endif
   res->SetInteger("buffers", buffers);
   res->SetInteger("cached", cached);
   res->SetInteger("active_anon", active_anon);
@@ -548,7 +581,6 @@
   res->SetInteger("swap_free", swap_free);
   res->SetInteger("swap_used", swap_total - swap_free);
   res->SetInteger("dirty", dirty);
-  res->SetInteger("reclaimable", reclaimable);
   res->SetInteger("pswpin", pswpin);
   res->SetInteger("pswpout", pswpout);
   res->SetInteger("pgmajfault", pgmajfault);
@@ -596,8 +628,10 @@
       target = &meminfo->total;
     else if (tokens[0] == "MemFree:")
       target = &meminfo->free;
+#if defined(OS_LINUX)
     else if (tokens[0] == "MemAvailable:")
       target = &meminfo->available;
+#endif
     else if (tokens[0] == "Buffers:")
       target = &meminfo->buffers;
     else if (tokens[0] == "Cached:")
@@ -616,8 +650,6 @@
       target = &meminfo->swap_free;
     else if (tokens[0] == "Dirty:")
       target = &meminfo->dirty;
-    else if (tokens[0] == "SReclaimable:")
-      target = &meminfo->reclaimable;
 #if defined(OS_CHROMEOS)
     // Chrome OS has a tweaked kernel that allows us to query Shmem, which is
     // usually video memory otherwise invisible to the OS.