diff --git a/webrtc/system_wrappers/interface/trace_event.h b/webrtc/system_wrappers/interface/trace_event.h
index a7995c5c83..fd581a43ee 100644
--- a/webrtc/system_wrappers/interface/trace_event.h
+++ b/webrtc/system_wrappers/interface/trace_event.h
@@ -146,12 +146,12 @@
 // By default, const char* argument values are assumed to have long-lived scope
 // and will not be copied. Use this macro to force a const char* to be copied.
 #define TRACE_STR_COPY(str) \
-    trace_event_internal::TraceStringWithCopy(str)
+    webrtc::trace_event_internal::TraceStringWithCopy(str)
 
 // By default, uint64 ID argument values are not mangled with the Process ID in
 // TRACE_EVENT_ASYNC macros. Use this macro to force Process ID mangling.
 #define TRACE_ID_MANGLE(id) \
-    trace_event_internal::TraceID::ForceMangle(id)
+    webrtc::trace_event_internal::TraceID::ForceMangle(id)
 
 // Records a pair of begin and end events called "name" for the current
 // scope, with 0, 1 or 2 associated arguments. If the category is not
@@ -618,9 +618,9 @@
     do { \
       INTERNAL_TRACE_EVENT_GET_CATEGORY_INFO(category); \
       if (*INTERNAL_TRACE_EVENT_UID(catstatic)) { \
-        trace_event_internal::AddTraceEvent( \
+        webrtc::trace_event_internal::AddTraceEvent(          \
             phase, INTERNAL_TRACE_EVENT_UID(catstatic), name, \
-            trace_event_internal::kNoEventId, flags, ##__VA_ARGS__); \
+            webrtc::trace_event_internal::kNoEventId, flags, ##__VA_ARGS__); \
       } \
     } while (0)
 
@@ -629,13 +629,13 @@
 // ends.
 #define INTERNAL_TRACE_EVENT_ADD_SCOPED(category, name, ...) \
     INTERNAL_TRACE_EVENT_GET_CATEGORY_INFO(category); \
-    trace_event_internal::TraceEndOnScopeClose \
+    webrtc::trace_event_internal::TraceEndOnScopeClose  \
         INTERNAL_TRACE_EVENT_UID(profileScope); \
     if (*INTERNAL_TRACE_EVENT_UID(catstatic)) { \
-      trace_event_internal::AddTraceEvent( \
+      webrtc::trace_event_internal::AddTraceEvent(      \
           TRACE_EVENT_PHASE_BEGIN, \
           INTERNAL_TRACE_EVENT_UID(catstatic), \
-          name, trace_event_internal::kNoEventId, \
+          name, webrtc::trace_event_internal::kNoEventId,       \
           TRACE_EVENT_FLAG_NONE, ##__VA_ARGS__); \
       INTERNAL_TRACE_EVENT_UID(profileScope).Initialize( \
           INTERNAL_TRACE_EVENT_UID(catstatic), name); \
@@ -647,14 +647,14 @@
 #define INTERNAL_TRACE_EVENT_ADD_SCOPED_IF_LONGER_THAN(threshold, \
         category, name, ...) \
     INTERNAL_TRACE_EVENT_GET_CATEGORY_INFO(category); \
-    trace_event_internal::TraceEndOnScopeCloseThreshold \
+    webrtc::trace_event_internal::TraceEndOnScopeCloseThreshold \
         INTERNAL_TRACE_EVENT_UID(profileScope); \
     if (*INTERNAL_TRACE_EVENT_UID(catstatic)) { \
       int INTERNAL_TRACE_EVENT_UID(begin_event_id) = \
-        trace_event_internal::AddTraceEvent( \
+        webrtc::trace_event_internal::AddTraceEvent( \
             TRACE_EVENT_PHASE_BEGIN, \
             INTERNAL_TRACE_EVENT_UID(catstatic), \
-            name, trace_event_internal::kNoEventId, \
+            name, webrtc::trace_event_internal::kNoEventId, \
             TRACE_EVENT_FLAG_NONE, ##__VA_ARGS__); \
       INTERNAL_TRACE_EVENT_UID(profileScope).Initialize( \
           INTERNAL_TRACE_EVENT_UID(catstatic), name, \
@@ -669,9 +669,9 @@
       INTERNAL_TRACE_EVENT_GET_CATEGORY_INFO(category); \
       if (*INTERNAL_TRACE_EVENT_UID(catstatic)) { \
         unsigned char trace_event_flags = flags | TRACE_EVENT_FLAG_HAS_ID; \
-        trace_event_internal::TraceID trace_event_trace_id( \
+        webrtc::trace_event_internal::TraceID trace_event_trace_id( \
             id, &trace_event_flags); \
-        trace_event_internal::AddTraceEvent( \
+        webrtc::trace_event_internal::AddTraceEvent( \
             phase, INTERNAL_TRACE_EVENT_UID(catstatic), \
             name, trace_event_trace_id.data(), trace_event_flags, \
             ##__VA_ARGS__); \
@@ -711,6 +711,7 @@
 #define TRACE_VALUE_TYPE_STRING       (static_cast<unsigned char>(6))
 #define TRACE_VALUE_TYPE_COPY_STRING  (static_cast<unsigned char>(7))
 
+namespace webrtc {
 namespace trace_event_internal {
 
 // Specify these values when the corresponding argument of AddTraceEvent is not
@@ -1014,5 +1015,6 @@ class TraceEndOnScopeCloseThreshold {
 };
 
 }  // namespace trace_event_internal
+}  // namespace webrtc
 
 #endif  // WEBRTC_SYSTEM_WRAPPERS_INTERFACE_TRACE_EVENT_H_