[wpe-2.38] Add ftrace based system tracing

Add WebKit tracing with linux 'ftrace' that can be used on STB devices.
Write tracing points into 'trace_marker' file with 'perfetto'
compatible format.
The results can be collected and visualized by 'perfetto'

Author: asurdej-comcast

Source/WTF/wtf/PlatformWPE.cmake

@@ -13,6 +13,7 @@ list(APPEND WTF_PUBLIC_HEADERS
     linux/ProcessMemoryFootprint.h
     linux/CurrentProcessMemoryStatus.h
     linux/RealTimeThreads.h
+    linux/SystemTracingFTrace.h
 
     unix/UnixFileDescriptor.h
 )

Source/WTF/wtf/SystemTracing.h

@@ -146,12 +146,21 @@ enum TracePointCode {
 
 #ifdef __cplusplus
 
+#if USE(LINUX_FTRACE)
+#include <wtf/linux/SystemTracingFTrace.h>
+#endif
+
 namespace WTF {
 
 inline void tracePoint(TracePointCode code, uint64_t data1 = 0, uint64_t data2 = 0, uint64_t data3 = 0, uint64_t data4 = 0)
 {
 #if HAVE(KDEBUG_H)
     kdebug_trace(ARIADNEDBG_CODE(WEBKIT_COMPONENT, code), data1, data2, data3, data4);
+#elif USE(LINUX_FTRACE)
+    SystemTracingFTrace::instance().tracePoint(code, data1);
+    UNUSED_PARAM(data2);
+    UNUSED_PARAM(data3);
+    UNUSED_PARAM(data4);
 #else
     UNUSED_PARAM(code);
     UNUSED_PARAM(data1);