base/trace_event: Remove unused LINK_IDS trace point support code

Bug: 1006539
Change-Id: Ie8788b614d2ce945974d45223e2044c58d7a04dd
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1988351
Auto-Submit: Sami Kyöstilä <skyostil@chromium.org>
Commit-Queue: Eric Seckler <eseckler@chromium.org>
Reviewed-by: Eric Seckler <eseckler@chromium.org>
Cr-Commit-Position: refs/heads/master@{#728511}

base/trace_event/common/trace_event_common.h

@@ -1079,7 +1079,6 @@
 #define TRACE_EVENT_PHASE_CLOCK_SYNC ('c')
 #define TRACE_EVENT_PHASE_ENTER_CONTEXT ('(')
 #define TRACE_EVENT_PHASE_LEAVE_CONTEXT (')')
-#define TRACE_EVENT_PHASE_LINK_IDS ('=')
 
 // Flags for changing the behavior of TRACE_EVENT_API_ADD_TRACE_EVENT.
 #define TRACE_EVENT_FLAG_NONE (static_cast<unsigned int>(0))

base/trace_event/trace_event.h

@@ -407,23 +407,6 @@
     }                                                                        \
   } while (0)
 
-// The linked ID will not be mangled.
-#define INTERNAL_TRACE_EVENT_ADD_LINK_IDS(category_group, name, id1, id2) \
-  do {                                                                    \
-    INTERNAL_TRACE_EVENT_GET_CATEGORY_INFO(category_group);               \
-    if (INTERNAL_TRACE_EVENT_CATEGORY_GROUP_ENABLED()) {                  \
-      trace_event_internal::TraceID source_id((id1));                     \
-      unsigned int source_flags = source_id.id_flags();                   \
-      trace_event_internal::TraceID target_id((id2));                     \
-      trace_event_internal::AddTraceEvent(                                \
-          TRACE_EVENT_PHASE_LINK_IDS,                                     \
-          INTERNAL_TRACE_EVENT_UID(category_group_enabled), name,         \
-          source_id.scope(), source_id.raw_id(), source_flags,            \
-          trace_event_internal::kNoId, "linked_id",                       \
-          target_id.AsConvertableToTraceFormat());                        \
-    }                                                                     \
-  } while (0)
-
 // Implementation detail: internal macro to create static category and add
 // metadata event if the category is enabled.
 #define INTERNAL_TRACE_EVENT_METADATA_ADD(category_group, name, ...) \
@@ -635,9 +618,6 @@ class BASE_EXPORT TraceID {
   unsigned long long prefix() const { return prefix_; }
   unsigned int id_flags() const { return id_flags_; }
 
-  std::unique_ptr<base::trace_event::ConvertableToTraceFormat>
-  AsConvertableToTraceFormat() const;
-
  private:
   const char* scope_ = nullptr;
   bool has_prefix_ = false;

base/trace_event/trace_event_impl.cc

@@ -311,42 +311,3 @@ void TraceEvent::AppendPrettyPrinted(std::ostringstream* out) const {
 
 }  // namespace trace_event
 }  // namespace base
-
-namespace trace_event_internal {
-
-std::unique_ptr<base::trace_event::ConvertableToTraceFormat>
-TraceID::AsConvertableToTraceFormat() const {
-  auto value = std::make_unique<base::trace_event::TracedValue>();
-
-  if (scope_ != kGlobalScope)
-    value->SetString("scope", scope_);
-
-  const char* id_field_name = "id";
-  if (id_flags_ == TRACE_EVENT_FLAG_HAS_GLOBAL_ID) {
-    id_field_name = "global";
-    value->BeginDictionary("id2");
-  } else if (id_flags_ == TRACE_EVENT_FLAG_HAS_LOCAL_ID) {
-    id_field_name = "local";
-    value->BeginDictionary("id2");
-  } else if (id_flags_ != TRACE_EVENT_FLAG_HAS_ID) {
-    NOTREACHED() << "Unrecognized ID flag";
-  }
-
-  if (has_prefix_) {
-    value->SetString(id_field_name,
-                     base::StringPrintf("0x%" PRIx64 "/0x%" PRIx64,
-                                        static_cast<uint64_t>(prefix_),
-                                        static_cast<uint64_t>(raw_id_)));
-  } else {
-    value->SetString(
-        id_field_name,
-        base::StringPrintf("0x%" PRIx64, static_cast<uint64_t>(raw_id_)));
-  }
-
-  if (id_flags_ != TRACE_EVENT_FLAG_HAS_ID)
-    value->EndDictionary();
-
-  return std::move(value);
-}
-
-}  // namespace trace_event_internal