Add compile time checks against longs being used in IPC structs on 32 bit Android.

base/trace_event/trace_log.cc

Index: base/trace_event/trace_log.cc
diff --git a/base/trace_event/trace_log.cc b/base/trace_event/trace_log.cc
index 5dc38bfcca747fea5ade453e8cef38c53f6a7144..655d4972fa4ba5487801cdd1141d214d8eda01f4 100644
--- a/base/trace_event/trace_log.cc
+++ b/base/trace_event/trace_log.cc
@@ -756,8 +756,8 @@ bool TraceLog::HasEnabledStateObserver(EnabledStateObserver* listener) const {
 TraceLogStatus TraceLog::GetStatus() const {
   AutoLock lock(lock_);
   TraceLogStatus result;
-  result.event_capacity = logged_events_->Capacity();
-  result.event_count = logged_events_->Size();
+  result.event_capacity = static_cast<uint32_t>(logged_events_->Capacity());
+  result.event_count = static_cast<uint32_t>(logged_events_->Size());
   return result;
 }