[tracing] Introduce MemoryDumpArgs to enable light and heavy dumps

base/trace_event/process_memory_maps_dump_provider.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 "base/trace_event/process_memory_maps_dump_provider.h"
 
 #include <cctype>
 #include <fstream>
 
 #include "base/logging.h"
@@ skipping 145 matching lines @@
   return Singleton<ProcessMemoryMapsDumpProvider,
                    LeakySingletonTraits<ProcessMemoryMapsDumpProvider>>::get();
 }
 
 ProcessMemoryMapsDumpProvider::ProcessMemoryMapsDumpProvider() {
 }
 
 ProcessMemoryMapsDumpProvider::~ProcessMemoryMapsDumpProvider() {
 }
 
-// Called at trace dump point time. Creates a snapshot the memory maps for the
-// current process.
-bool ProcessMemoryMapsDumpProvider::OnMemoryDump(ProcessMemoryDump* pmd) {
+// Called at trace dump point time. Creates a snapshot of the memory maps for
+// the current process.
+bool ProcessMemoryMapsDumpProvider::OnMemoryDump(const MemoryDumpArgs& args,
+                                                 ProcessMemoryDump* pmd) {
+  // TODO(ssid): Use MemoryDumpArgs to create light dumps when requested
+  // (crbug.com/499731).
+
   uint32 res = 0;
 
 #if defined(OS_LINUX) || defined(OS_ANDROID)
   if (UNLIKELY(proc_smaps_for_testing)) {
     res = ReadLinuxProcSmapsFile(proc_smaps_for_testing, pmd->process_mmaps());
   } else {
     std::ifstream proc_self_smaps("/proc/self/smaps");
     res = ReadLinuxProcSmapsFile(&proc_self_smaps, pmd->process_mmaps());
   }
 #else
   LOG(ERROR) << "ProcessMemoryMaps dump provider is supported only on Linux";
 #endif
 
   if (res > 0) {
     pmd->set_has_process_mmaps();
     return true;
   }
 
   return false;
 }
 
 }  // namespace trace_event
 }  // namespace base