Fix some clang warnings with -Wmissing-braces in base.

base/trace_event/trace_event_win.cc

Index: base/trace_event/trace_event_win.cc
diff --git a/base/trace_event/trace_event_win.cc b/base/trace_event/trace_event_win.cc
index ebb55c844923daf84b80472cd53a6bffaff7c599..fdbd35a0e2feda383072f9c3e78a1b5668b919e1 100644
--- a/base/trace_event/trace_event_win.cc
+++ b/base/trace_event/trace_event_win.cc
@@ -16,16 +16,24 @@ using base::win::EtwMofEvent;
 
 // {3DADA31D-19EF-4dc1-B345-037927193422}
 const GUID kChromeTraceProviderName = {
-    0x3dada31d, 0x19ef, 0x4dc1, 0xb3, 0x45, 0x3, 0x79, 0x27, 0x19, 0x34, 0x22 };
+    0x3dada31d,
+    0x19ef,
+    0x4dc1,
+    {0xb3, 0x45, 0x3, 0x79, 0x27, 0x19, 0x34, 0x22}};
 
 // {B967AE67-BB22-49d7-9406-55D91EE1D560}
 const GUID kTraceEventClass32 = {
-    0xb967ae67, 0xbb22, 0x49d7, 0x94, 0x6, 0x55, 0xd9, 0x1e, 0xe1, 0xd5, 0x60 };
+    0xb967ae67,
+    0xbb22,
+    0x49d7,
+    {0x94, 0x6, 0x55, 0xd9, 0x1e, 0xe1, 0xd5, 0x60}};
 
 // {97BE602D-2930-4ac3-8046-B6763B631DFE}
 const GUID kTraceEventClass64 = {
-    0x97be602d, 0x2930, 0x4ac3, 0x80, 0x46, 0xb6, 0x76, 0x3b, 0x63, 0x1d, 0xfe};
-
+    0x97be602d,
+    0x2930,
+    0x4ac3,
+    {0x80, 0x46, 0xb6, 0x76, 0x3b, 0x63, 0x1d, 0xfe}};
 
 TraceEventETWProvider::TraceEventETWProvider() :
     EtwTraceProvider(kChromeTraceProviderName) {