Bug 736898: Avoid signed/unsigned comparisons in tools/profiler, r=bgirard

--HG--
extra : rebase_source : 53eadd48e29fc1aae143b0480bcb573a392e1130

tools/profiler/TableTicker.cpp

@@ -580,7 +580,7 @@ void doSampleStackTrace(ProfileStack *aStack, ThreadProfile &aProfile, TickSampl
   // Sample
   // 's' tag denotes the start of a sample block
   // followed by 0 or more 'c' tags.
-  for (int i = 0; i < aStack->mStackPointer; i++) {
+  for (mozilla::sig_safe_t i = 0; i < aStack->mStackPointer; i++) {
     if (i == 0) {
       Address pc = 0;
       if (sample) {

tools/profiler/sps_sampler.h

@@ -212,7 +212,8 @@ public:
     if (mQueueClearMarker) {
       clearMarkers();
     }
-    if (aMarkerId >= mMarkerPointer) {
+    if (aMarkerId < 0 ||
+	static_cast<mozilla::sig_safe_t>(aMarkerId) >= mMarkerPointer) {
       return NULL;
     }
     return mMarkers[aMarkerId];