Fix NiceValueToThreadPriority failing on an unknown nice value.

base/threading/platform_thread_unittest.cc

Index: base/threading/platform_thread_unittest.cc
diff --git a/base/threading/platform_thread_unittest.cc b/base/threading/platform_thread_unittest.cc
index 673877556a1f0550415be3db522715073b613855..baf6bf66732183045fb3b5994aee613d12c61ebd 100644
--- a/base/threading/platform_thread_unittest.cc
+++ b/base/threading/platform_thread_unittest.cc
@@ -14,6 +14,7 @@
 #if defined(OS_POSIX)
 #include <sys/types.h>
 #include <unistd.h>
+#include "base/threading/platform_thread_internal_posix.h"
 #elif defined(OS_WIN)
 #include <windows.h>
 #endif
@@ -271,4 +272,21 @@ TEST(PlatformThreadTest, ThreadPriorityCurrentThread) {
   }
 }
 
+#if defined(OS_LINUX)
+TEST(PlatformThreadTest, GetNiceValueToThreadPriority) {
+  using internal::NiceValueToThreadPriority;
+  EXPECT_EQ(ThreadPriority::BACKGROUND, NiceValueToThreadPriority(19));

[gab, 2016/04/08 15:52:51]

To make these cross-platform (well on OS_POSIX) you could extract the underlying
value from the map (it's okay to include the internal header in tests IMO),
would also make it clearer what's being tested IMO (e.g. NORMAL+1, etc.)

[Yuta Kitamura, 2016/04/12 10:19:00]

Yeah, updated the tests so they work on OS_POSIX.

+  EXPECT_EQ(ThreadPriority::BACKGROUND, NiceValueToThreadPriority(11));
+  EXPECT_EQ(ThreadPriority::BACKGROUND, NiceValueToThreadPriority(10));
+  EXPECT_EQ(ThreadPriority::BACKGROUND, NiceValueToThreadPriority(9));
+  EXPECT_EQ(ThreadPriority::BACKGROUND, NiceValueToThreadPriority(1));
+  EXPECT_EQ(ThreadPriority::NORMAL, NiceValueToThreadPriority(0));
+  EXPECT_EQ(ThreadPriority::NORMAL, NiceValueToThreadPriority(-7));
+  EXPECT_EQ(ThreadPriority::DISPLAY, NiceValueToThreadPriority(-8));
+  EXPECT_EQ(ThreadPriority::DISPLAY, NiceValueToThreadPriority(-9));
+  EXPECT_EQ(ThreadPriority::REALTIME_AUDIO, NiceValueToThreadPriority(-10));
+  EXPECT_EQ(ThreadPriority::REALTIME_AUDIO, NiceValueToThreadPriority(-20));
+}
+#endif
+
 }  // namespace base