base: Stop passing by non-const references in some more places.

base/trace_event/trace_event_impl.cc

 // Copyright (c) 2012 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/trace_event_impl.h"
 
 #include <algorithm>
 
 #include "base/base_switches.h"
 #include "base/bind.h"
@@ skipping 412 matching lines @@
   cloned_chunk->next_free_ = next_free_;
   for (size_t i = 0; i < next_free_; ++i)
     cloned_chunk->chunk_[i].CopyFrom(chunk_[i]);
   return cloned_chunk.Pass();
 }
 
 // A helper class that allows the lock to be acquired in the middle of the scope
 // and unlocks at the end of scope if locked.
 class TraceLog::OptionalAutoLock {
  public:
-  explicit OptionalAutoLock(Lock& lock)
-      : lock_(lock),
-        locked_(false) {
-  }
+  explicit OptionalAutoLock(Lock* lock) : lock_(lock), locked_(false) {}
 
   ~OptionalAutoLock() {
     if (locked_)
-      lock_.Release();
+      lock_->Release();
   }
 
   void EnsureAcquired() {
     if (!locked_) {
-      lock_.Acquire();
+      lock_->Acquire();
       locked_ = true;
     }
   }
 
  private:
-  Lock& lock_;
+  Lock* lock_;
   bool locked_;
   DISALLOW_COPY_AND_ASSIGN(OptionalAutoLock);
 };
 
 // Use this function instead of TraceEventHandle constructor to keep the
 // overhead of ScopedTracer (trace_event.h) constructor minimum.
 void MakeHandle(uint32 chunk_seq, size_t chunk_index, size_t event_index,
                 TraceEventHandle* handle) {
   DCHECK(chunk_seq);
   DCHECK(chunk_index < (1u << 16));
@@ skipping 1508 matching lines @@
             existing_name->second.push_back(',');
           existing_name->second.append(new_name);
         }
       }
     }
   }
 
   std::string console_message;
   if (*category_group_enabled &
       (ENABLED_FOR_RECORDING | ENABLED_FOR_MONITORING)) {
-    OptionalAutoLock lock(lock_);
+    OptionalAutoLock lock(&lock_);
 
     TraceEvent* trace_event = NULL;
     if (thread_local_event_buffer) {
       trace_event = thread_local_event_buffer->AddTraceEvent(&handle);
     } else {
       lock.EnsureAcquired();
       trace_event = AddEventToThreadSharedChunkWhileLocked(&handle, true);
     }
 
     if (trace_event) {
@@ skipping 132 matching lines @@
   if (thread_is_in_trace_event_.Get())
     return;
 
   AutoThreadLocalBoolean thread_is_in_trace_event(&thread_is_in_trace_event_);
 
   TimeTicks thread_now = ThreadNow();
   TimeTicks now = OffsetNow();
 
   std::string console_message;
   if (*category_group_enabled & ENABLED_FOR_RECORDING) {
-    OptionalAutoLock lock(lock_);
+    OptionalAutoLock lock(&lock_);
 
     TraceEvent* trace_event = GetEventByHandleInternal(handle, &lock);
     if (trace_event) {
       DCHECK(trace_event->phase() == TRACE_EVENT_PHASE_COMPLETE);
       trace_event->UpdateDuration(now, thread_now);
 #if defined(OS_ANDROID)
       trace_event->SendToATrace();
 #endif
     }
 
@@ skipping 461 matching lines @@
 }
 
 ScopedTraceBinaryEfficient::~ScopedTraceBinaryEfficient() {
   if (*category_group_enabled_) {
     TRACE_EVENT_API_UPDATE_TRACE_EVENT_DURATION(category_group_enabled_,
                                                 name_, event_handle_);
   }
 }
 
 }  // namespace trace_event_internal