Reland of [tracing] Dump child processes' memory metrics in browser

components/tracing.gyp

Index: components/tracing.gyp
diff --git a/components/tracing.gyp b/components/tracing.gyp
index d0d76773bddb3f35744350699fb023a1cb77a41f..9466a1c8aa2618f1cbbcbd944a56fd1a4befdfd1 100644
--- a/components/tracing.gyp
+++ b/components/tracing.gyp
@@ -32,6 +32,8 @@
         'tracing/child_trace_message_filter.h',
         'tracing/graphics_memory_dump_provider_android.cc',
         'tracing/graphics_memory_dump_provider_android.h',
+        'tracing/process_metrics_memory_dump_provider.cc',
+        'tracing/process_metrics_memory_dump_provider.h',
         'tracing/trace_config_file.cc',
         'tracing/trace_config_file.h',
         'tracing/trace_to_console.cc',
@@ -42,6 +44,13 @@
         'tracing/tracing_switches.cc',
         'tracing/tracing_switches.h',
       ],
+      'target_conditions': [
+        ['>(nacl_untrusted_build)==1', {
+          'sources!': [
+            'tracing/process_metrics_memory_dump_provider.cc',
+          ],
+        }],
+      ]
     },
   ],
 }