Work around a kernel bug on Android.

runtime/vm/thread_interrupter_macos.cc

Index: runtime/vm/thread_interrupter_macos.cc
diff --git a/runtime/vm/thread_interrupter_macos.cc b/runtime/vm/thread_interrupter_macos.cc
index e46dbc7d2a77f19d82e3d873d4d75169e975915b..be1d75af2a0051c2c94f4ced83571b1fd9153cfc 100644
--- a/runtime/vm/thread_interrupter_macos.cc
+++ b/runtime/vm/thread_interrupter_macos.cc
@@ -20,29 +20,27 @@ namespace dart {
 DECLARE_FLAG(bool, thread_interrupter);
 DECLARE_FLAG(bool, trace_thread_interrupter);
 
-class ThreadInterrupterMacOS : public AllStatic {
- public:
-  static void ThreadInterruptSignalHandler(int signal, siginfo_t* info,
-                                           void* context_) {
-    if (signal != SIGPROF) {
-      return;
-    }
-    Thread* thread = Thread::Current();
-    if (thread == NULL) {
-      return;
-    }
-    // Extract thread state.
-    ucontext_t* context = reinterpret_cast<ucontext_t*>(context_);
-    mcontext_t mcontext = context->uc_mcontext;
-    InterruptedThreadState its;
-    its.pc = SignalHandler::GetProgramCounter(mcontext);
-    its.fp = SignalHandler::GetFramePointer(mcontext);
-    its.csp = SignalHandler::GetCStackPointer(mcontext);
-    its.dsp = SignalHandler::GetDartStackPointer(mcontext);
-    its.lr = SignalHandler::GetLinkRegister(mcontext);
-    Profiler::SampleThread(thread, its);
+
+static void ThreadInterruptSignalHandler(int signal, siginfo_t* info,
+                                         void* context_) {
+  if (signal != SIGPROF) {
+    return;
+  }
+  Thread* thread = Thread::Current();
+  if (thread == NULL) {
+    return;
   }
-};
+  // Extract thread state.
+  ucontext_t* context = reinterpret_cast<ucontext_t*>(context_);
+  mcontext_t mcontext = context->uc_mcontext;
+  InterruptedThreadState its;
+  its.pc = SignalHandler::GetProgramCounter(mcontext);
+  its.fp = SignalHandler::GetFramePointer(mcontext);
+  its.csp = SignalHandler::GetCStackPointer(mcontext);
+  its.dsp = SignalHandler::GetDartStackPointer(mcontext);
+  its.lr = SignalHandler::GetLinkRegister(mcontext);
+  Profiler::SampleThread(thread, its);
+}
 
 
 void ThreadInterrupter::InterruptThread(OSThread* thread) {
@@ -55,7 +53,7 @@ void ThreadInterrupter::InterruptThread(OSThread* thread) {
 
 
 void ThreadInterrupter::InstallSignalHandler() {
-  SignalHandler::Install(ThreadInterrupterMacOS::ThreadInterruptSignalHandler);
+  SignalHandler::Install(ThreadInterruptSignalHandler);
 }