Use movable types for CallStackProfile(s) to remove copying of data.

components/metrics/child_call_stack_profile_collector.h

 // Copyright 2016 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 COMPONENTS_METRICS_CHILD_CALL_STACK_PROFILE_COLLECTOR_H_
 #define COMPONENTS_METRICS_CHILD_CALL_STACK_PROFILE_COLLECTOR_H_
 
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/single_thread_task_runner.h"
@@ skipping 47 matching lines @@
   // Sets the CallStackProfileCollector interface from |parent_collector|. This
   // function MUST be invoked exactly once, regardless of whether
   // |parent_collector| is null, as it flushes pending data in either case.
   void SetParentProfileCollector(
       metrics::mojom::CallStackProfileCollectorPtr parent_collector);
 
  private:
   friend class ChildCallStackProfileCollectorTest;
 
   // Bundles together a set of collected profiles and the collection state for
-  // storage, pending availability of the parent mojo interface.
+  // storage, pending availability of the parent mojo interface. |profiles|
+  // is not const& because it must be passed with std::move.
   struct ProfilesState {
     ProfilesState();
-    ProfilesState(const ProfilesState&);
+    ProfilesState(ProfilesState&&);
     ProfilesState(
         const CallStackProfileParams& params,
         base::TimeTicks start_timestamp,
-        const base::StackSamplingProfiler::CallStackProfiles& profiles);
+        base::StackSamplingProfiler::CallStackProfiles profiles);
     ~ProfilesState();
 
+    ProfilesState& operator=(ProfilesState&&);
+
     CallStackProfileParams params;
     base::TimeTicks start_timestamp;
 
     // The sampled profiles.
     base::StackSamplingProfiler::CallStackProfiles profiles;
+
+   private:
+    DISALLOW_COPY_AND_ASSIGN(ProfilesState);
   };
 
   using CallStackProfile = base::StackSamplingProfiler::CallStackProfile;
 
   void Collect(const CallStackProfileParams& params,
                base::TimeTicks start_timestamp,
-               const std::vector<CallStackProfile>& profiles);
+               std::vector<CallStackProfile> profiles);
 
   // This object may be accessed on any thread, including the profiler
   // thread. The expected use case for the object is to be created and have
   // GetProfilerCallback before the message loop starts, which prevents the use
   // of PostTask and the like for inter-thread communication.
   base::Lock lock_;
 
   // Whether to retain profiles when the interface is not set. Remains true
   // until the invocation of SetParentProfileCollector(), at which point it is
   // false for the rest of the object lifetime.
@@ skipping 11 matching lines @@
   // Profiles being cached by this object, pending a parent interface to be
   // supplied.
   std::vector<ProfilesState> profiles_;
 
   DISALLOW_COPY_AND_ASSIGN(ChildCallStackProfileCollector);
 };
 
 }  // namespace metrics
 
 #endif  // COMPONENTS_METRICS_CHILD_CALL_STACK_PROFILE_COLLECTOR_H_