Fix to use ucontext_t in unwind.h.

third_party/tcmalloc/chromium/src/profiler.cc

 // Copyright (c) 2005, Google Inc.
 // All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 // notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
@@ skipping 252 matching lines @@
 void CpuProfiler::prof_handler(int sig, siginfo_t*, void* signal_ucontext,
                                void* cpu_profiler) {
   CpuProfiler* instance = static_cast<CpuProfiler*>(cpu_profiler);
 
   if (instance->filter_ == NULL ||
       (*instance->filter_)(instance->filter_arg_)) {
     void* stack[ProfileData::kMaxStackDepth];
 
     // The top-most active routine doesn't show up as a normal
     // frame, but as the "pc" value in the signal handler context.
+#if defined(__ANDROID__)
+    stack[0] = GetPC(*reinterpret_cast<tcmalloc::ucontext_t*>(signal_ucontext));
+#else
     stack[0] = GetPC(*reinterpret_cast<ucontext_t*>(signal_ucontext));
+#endif
 
     // We skip the top two stack trace entries (this function and one
     // signal handler frame) since they are artifacts of profiling and
     // should not be measured.  Other profiling related frames may be
     // removed by "pprof" at analysis time.  Instead of skipping the top
     // frames, we could skip nothing, but that would increase the
     // profile size unnecessarily.
     int depth = GetStackTraceWithContext(stack + 1, arraysize(stack) - 1,
                                          2, signal_ucontext);
     depth++;  // To account for pc value in stack[0];
@@ skipping 51 matching lines @@
 extern "C" void ProfilerStop() { }
 extern "C" void ProfilerGetCurrentState(ProfilerState* state) {
   memset(state, 0, sizeof(*state));
 }
 
 #endif  // OS_CYGWIN
 
 // DEPRECATED routines
 extern "C" PERFTOOLS_DLL_DECL void ProfilerEnable() { }
 extern "C" PERFTOOLS_DLL_DECL void ProfilerDisable() { }