[tracing] Introduce MemoryDumpArgs to enable light and heavy dumps

content/child/web_memory_dump_provider_adapter.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/child/web_memory_dump_provider_adapter.h"
 
 #include "content/child/web_process_memory_dump_impl.h"
 #include "third_party/WebKit/public/platform/WebMemoryDumpProvider.h"
 
 namespace content {
 
 WebMemoryDumpProviderAdapter::WebMemoryDumpProviderAdapter(
     blink::WebMemoryDumpProvider* wmdp)
     : web_memory_dump_provider_(wmdp), is_registered_(false) {
 }
 
 WebMemoryDumpProviderAdapter::~WebMemoryDumpProviderAdapter() {
   DCHECK(!is_registered_);
 }
 
 bool WebMemoryDumpProviderAdapter::OnMemoryDump(
+    const base::trace_event::MemoryDumpArgs& args,
     base::trace_event::ProcessMemoryDump* pmd) {
+  // TODO(ssid): Expose MemoryDumpArgs to Blink and send args to the dump
+  // providers in Blink (crbug.com/499731).
   WebProcessMemoryDumpImpl web_pmd_impl(pmd);
   return web_memory_dump_provider_->onMemoryDump(&web_pmd_impl);
 }
 
 }  // namespace content