Add chrome.memoryBenchmarking.requestMemoryDump() API

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 "base/atomic_sequence_num.h"
 #include "base/compiler_specific.h"
@@ skipping 254 matching lines @@
                              pmd_async_state->task_runner,
                              pmd_async_state->req_args.dump_guid);
     }
 
     auto* mdp_info = &*pmd_async_state->next_dump_provider;
     mdp = mdp_info->dump_provider;
     if (mdp_info->disabled) {
       skip_dump = true;
     } else if (mdp == g_mmaps_dump_provider &&
                pmd_async_state->req_args.dump_type !=
-                   MemoryDumpType::PERIODIC_INTERVAL_WITH_MMAPS) {
+                   MemoryDumpType::PERIODIC_INTERVAL_WITH_MMAPS &&
+               pmd_async_state->req_args.dump_type !=
+                   MemoryDumpType::EXPLICITLY_TRIGGERED) {
       // Mmaps dumping is very heavyweight and cannot be performed at the same
       // rate of other dumps. TODO(primiano): this is a hack and should be
       // cleaned up as part of crbug.com/499731.
       skip_dump = true;
     } else if (mdp_info->task_runner &&
                !mdp_info->task_runner->BelongsToCurrentThread()) {
       // It's time to hop onto another thread.
 
       // Copy the callback + arguments just for the unlikley case in which
       // PostTask fails. In such case the Bind helper will destroy the
@@ skipping 184 matching lines @@
       next_dump_provider(next_dump_provider),
       callback(callback),
       task_runner(MessageLoop::current()->task_runner()) {
 }
 
 MemoryDumpManager::ProcessMemoryDumpAsyncState::~ProcessMemoryDumpAsyncState() {
 }
 
 }  // namespace trace_event
 }  // namespace base