[memory-infra] Remove MemoryDumpManagerDelegate

base/trace_event/memory_dump_manager.h

Index: base/trace_event/memory_dump_manager.h
diff --git a/base/trace_event/memory_dump_manager.h b/base/trace_event/memory_dump_manager.h
index d359a8c3e9722f8441c907d06a2ae3b91cc8b7c8..f29c68ad6c1a3064eea6f28f96b870b6c72954d5 100644
--- a/base/trace_event/memory_dump_manager.h
+++ b/base/trace_event/memory_dump_manager.h
@@ -24,11 +24,11 @@
 #include "base/trace_event/process_memory_dump.h"
 #include "base/trace_event/trace_event.h"
 
-// Forward declare |MemoryDumpManagerDelegateImplTest| so that we can make it a
+// Forward declare |ProcessLocalDumpManagerImplTest| so that we can make it a
 // friend of |MemoryDumpManager| and give it access to |SetInstanceForTesting|.
 namespace memory_instrumentation {
 
-class MemoryDumpManagerDelegateImplTest;
+class ProcessLocalDumpManagerImplTest;
 
 }  // namespace memory_instrumentation
 
@@ -39,7 +39,6 @@ class Thread;
 
 namespace trace_event {
 
-class MemoryDumpManagerDelegate;
 class MemoryDumpProvider;
 class MemoryDumpSessionState;
 
@@ -48,6 +47,10 @@ class MemoryDumpSessionState;
 // RequestDumpPoint(). The extension by Un(RegisterDumpProvider).
 class BASE_EXPORT MemoryDumpManager : public TraceLog::EnabledStateObserver {
  public:
+  using RequestGlobalDumpFunction =
+      RepeatingCallback<void(const MemoryDumpRequestArgs& args,
+                             const GlobalMemoryDumpCallback& callback)>;
+
   static const char* const kTraceCategory;
   static const char* const kLogPrefix;
 
@@ -63,10 +66,12 @@ class BASE_EXPORT MemoryDumpManager : public TraceLog::EnabledStateObserver {
   // On the other side, the MemoryDumpManager will not be fully operational
   // (i.e. will NACK any RequestGlobalMemoryDump()) until initialized.
   // Arguments:
-  //  delegate: inversion-of-control interface for embedder-specific behaviors
-  //      (multiprocess handshaking). See the lifetime and thread-safety
-  //      requirements in the |MemoryDumpManagerDelegate| docstring.
-  void Initialize(std::unique_ptr<MemoryDumpManagerDelegate> delegate);
+  //  request_dump_function: Function to invoke a global dump. Global dump
+  //      involves embedder-specific behaviors like multiprocess handshaking.
+  //  is_coordinator: True when current process coodinates the periodic dump
+  //      triggering.
+  void Initialize(RequestGlobalDumpFunction request_dump_function,
+                  bool is_coordinator);
 
   // (Un)Registers a MemoryDumpProvider instance.
   // Args:
@@ -119,6 +124,14 @@ class BASE_EXPORT MemoryDumpManager : public TraceLog::EnabledStateObserver {
   void RequestGlobalDump(MemoryDumpType dump_type,
                          MemoryDumpLevelOfDetail level_of_detail);
 
+  // NOTE: Use RequestGlobalDump() to create memory dumps. Creates a memory dump
+  // for the current process and appends it to the trace. |callback| will be
+  // invoked asynchronously upon completion on the same thread on which
+  // CreateProcessDump() was called. This method should only be used by the
+  // embedder while creating a global memory dump.
+  void CreateProcessDump(const MemoryDumpRequestArgs& args,
+                         const ProcessMemoryDumpCallback& callback);
+
   // TraceLog::EnabledStateObserver implementation.
   void OnTraceLogEnabled() override;
   void OnTraceLogDisabled() override;
@@ -165,9 +178,8 @@ class BASE_EXPORT MemoryDumpManager : public TraceLog::EnabledStateObserver {
  private:
   friend std::default_delete<MemoryDumpManager>;  // For the testing instance.
   friend struct DefaultSingletonTraits<MemoryDumpManager>;
-  friend class MemoryDumpManagerDelegate;
   friend class MemoryDumpManagerTest;
-  friend class memory_instrumentation::MemoryDumpManagerDelegateImplTest;
+  friend class memory_instrumentation::ProcessLocalDumpManagerImplTest;
 
   // Holds the state of a process memory dump that needs to be carried over
   // across task runners in order to fulfil an asynchronous CreateProcessDump()
@@ -237,13 +249,6 @@ class BASE_EXPORT MemoryDumpManager : public TraceLog::EnabledStateObserver {
   static void FinalizeDumpAndAddToTrace(
       std::unique_ptr<ProcessMemoryDumpAsyncState> pmd_async_state);
 
-  // Internal, used only by MemoryDumpManagerDelegate.
-  // Creates a memory dump for the current process and appends it to the trace.
-  // |callback| will be invoked asynchronously upon completion on the same
-  // thread on which CreateProcessDump() was called.
-  void CreateProcessDump(const MemoryDumpRequestArgs& args,
-                         const ProcessMemoryDumpCallback& callback);
-
   // Calls InvokeOnMemoryDump() for the next MDP on the task runner specified by
   // the MDP while registration. On failure to do so, skips and continues to
   // next MDP.
@@ -283,10 +288,14 @@ class BASE_EXPORT MemoryDumpManager : public TraceLog::EnabledStateObserver {
   std::unordered_set<StringPiece, StringPieceHash>
       strict_thread_check_blacklist_;
 
-  std::unique_ptr<MemoryDumpManagerDelegate> delegate_;
+  // Function provided by the embedder to handle global dump requests.
+  RequestGlobalDumpFunction request_dump_function_;
 
-  // Protects from concurrent accesses to the |dump_providers_*| and |delegate_|
-  // to guard against disabling logging while dumping on another thread.
+  // True when current process coordinates the periodic dump triggering.
+  bool is_coordinator_;
+
+  // Protects from concurrent accesses to the local state, eg: to guard against
+  // disabling logging while dumping on another thread.
   Lock lock_;
 
   // Optimization to avoid attempting any memory dump (i.e. to not walk an empty
@@ -310,29 +319,6 @@ class BASE_EXPORT MemoryDumpManager : public TraceLog::EnabledStateObserver {
   DISALLOW_COPY_AND_ASSIGN(MemoryDumpManager);
 };
 
-// The delegate is supposed to be long lived (read: a Singleton) and thread
-// safe (i.e. should expect calls from any thread and handle thread hopping).
-class BASE_EXPORT MemoryDumpManagerDelegate {
- public:
-  MemoryDumpManagerDelegate() {}
-  virtual ~MemoryDumpManagerDelegate() {}
-
-  virtual void RequestGlobalMemoryDump(
-      const MemoryDumpRequestArgs& args,
-      const GlobalMemoryDumpCallback& callback) = 0;
-
-  virtual bool IsCoordinator() const = 0;
-
- protected:
-  void CreateProcessDump(const MemoryDumpRequestArgs& args,
-                         const ProcessMemoryDumpCallback& callback) {
-    MemoryDumpManager::GetInstance()->CreateProcessDump(args, callback);
-  }
-
- private:
-  DISALLOW_COPY_AND_ASSIGN(MemoryDumpManagerDelegate);
-};
-
 }  // namespace trace_event
 }  // namespace base