Fix crash in InvokeOnMemoryDump when tracing

base/trace_event/memory_dump_manager.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/memory_dump_manager.h"
 
 #include <algorithm>
 #include <utility>
 
 #include "base/allocator/features.h"
@@ skipping 465 matching lines @@
   MemoryDumpRequestArgs args = {guid, dump_type, level_of_detail};
   delegate->RequestGlobalMemoryDump(args, wrapped_callback);
 }
 
 void MemoryDumpManager::RequestGlobalDump(
     MemoryDumpType dump_type,
     MemoryDumpLevelOfDetail level_of_detail) {
   RequestGlobalDump(dump_type, level_of_detail, MemoryDumpCallback());
 }
 
+bool MemoryDumpManager::IsDumpProviderRegisteredForTesting(
+    MemoryDumpProvider* provider) {
+  AutoLock lock(lock_);
+
+  auto mdp_iter = dump_providers_.begin();

[Primiano Tucci (use gerrit), 2017/03/15 12:44:40]

you can use C++11 foreach these days, which is quite neat. Makes it look like a
20th century language. 
It should be something like:

for (const auto& mdp : dump_providers) ...

[hjd, 2017/03/15 14:23:12]

Done, thanks!

+  for (; mdp_iter != dump_providers_.end(); ++mdp_iter) {
+    if ((*mdp_iter)->dump_provider == provider)
+      return true;
+  }
+  return false;
+}
+
 void MemoryDumpManager::CreateProcessDump(const MemoryDumpRequestArgs& args,
                                           const MemoryDumpCallback& callback) {
   TRACE_EVENT_NESTABLE_ASYNC_BEGIN0(kTraceCategory, "ProcessMemoryDump",
                                     TRACE_ID_MANGLE(args.dump_guid));
 
   // If argument filter is enabled then only background mode dumps should be
   // allowed. In case the trace config passed for background tracing session
   // missed the allowed modes argument, it crashes here instead of creating
   // unexpected dumps.
   if (TraceLog::GetInstance()
@@ skipping 472 matching lines @@
   if (iter == process_dumps.end()) {
     std::unique_ptr<ProcessMemoryDump> new_pmd(
         new ProcessMemoryDump(session_state, dump_args));
     iter = process_dumps.insert(std::make_pair(pid, std::move(new_pmd))).first;
   }
   return iter->second.get();
 }
 
 }  // namespace trace_event
 }  // namespace base