[memory-infra] Add api to enable heap profiling in MemoryDumpManager

base/trace_event/heap_profiler_allocation_context_tracker.h

 // 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.
 
 #ifndef BASE_TRACE_EVENT_HEAP_PROFILER_ALLOCATION_CONTEXT_TRACKER_H_
 #define BASE_TRACE_EVENT_HEAP_PROFILER_ALLOCATION_CONTEXT_TRACKER_H_
 
 #include <vector>
 
 #include "base/atomicops.h"
 #include "base/base_export.h"
 #include "base/debug/stack_trace.h"
 #include "base/macros.h"
 #include "base/trace_event/heap_profiler_allocation_context.h"
 
 namespace base {
 namespace trace_event {
 
 // The allocation context tracker keeps track of thread-local context for heap
 // profiling. It includes a pseudo stack of trace events. On every allocation
 // the tracker provides a snapshot of its context in the form of an
 // |AllocationContext| that is to be stored together with the allocation
 // details.
 class BASE_EXPORT AllocationContextTracker {
  public:
-  enum class CaptureMode: int32_t {
-    DISABLED,       // Don't capture anything
-    PSEUDO_STACK,   // GetContextSnapshot() returns pseudo stack trace
-    NATIVE_STACK    // GetContextSnapshot() returns native (real) stack trace
+  enum class CaptureMode : int32_t {
+    DISABLED,      // Don't capture anything
+    PSEUDO_STACK,  // GetContextSnapshot() returns pseudo stack trace
+    NATIVE_STACK,  // GetContextSnapshot() returns native (real) stack trace
+    BACKGROUND,  // GetContextSnapshot() returns thread names and task contexts.
   };
 
   // Stack frame constructed from trace events in codebase.
   struct BASE_EXPORT PseudoStackFrame {
     const char* trace_event_category;
     const char* trace_event_name;
 
     bool operator==(const PseudoStackFrame& other) const {
       return trace_event_category == other.trace_event_category &&
              trace_event_name == other.trace_event_name;
@@ skipping 72 matching lines @@
 
   uint32_t ignore_scope_depth_;
 
   DISALLOW_COPY_AND_ASSIGN(AllocationContextTracker);
 };
 
 }  // namespace trace_event
 }  // namespace base
 
 #endif  // BASE_TRACE_EVENT_HEAP_PROFILER_ALLOCATION_CONTEXT_TRACKER_H_