Don't use 'defined' in macro expansion.

A careful reading of the preprocessor specification indicates that
any use of the 'defined' operator outside the form of 'defined X' or
'defined ( X )' directly in the constant expression of a '#if' or
'#elif' may cause undefined behavior.

In particular, msvc is very unpredictable. The 'defined X' and
'defined ( X )' forms behave differently when created from marco
expansion, with 'defined ( X )' generally evaluating to '0L'. The
'defined X' form generally behaves more the way one would expect,
but still has a number of quirks which should simply be considered
undefined behavior.

BUG=chromium:419245

Review URL: https://codereview.chromium.org/657183002
diff --git a/include/core/SkFloatingPoint.h b/include/core/SkFloatingPoint.h
index 2df8f9b..f85c456 100644
--- a/include/core/SkFloatingPoint.h
+++ b/include/core/SkFloatingPoint.h
@@ -32,8 +32,12 @@
 static inline float sk_float_copysign(float x, float y) {
 // c++11 contains a 'float copysign(float, float)' function in <cmath>.
 // clang-cl reports __cplusplus for clang, not the __cplusplus vc++ version _MSC_VER would report.
-#define SK_BUILD_WITH_CLANG_CL (defined(_MSC_VER) && defined(__clang__))
-#if (!SK_BUILD_WITH_CLANG_CL && __cplusplus >= 201103L) || (defined(_MSC_VER) && _MSC_VER >= 1800)
+#if (defined(_MSC_VER) && defined(__clang__))
+#    define SK_BUILD_WITH_CLANG_CL 1
+#else
+#    define SK_BUILD_WITH_CLANG_CL 0
+#endif
+#if (!SK_BUILD_WITH_CLANG_CL && __cplusplus >= 201103L) || (_MSC_VER >= 1800)
     return copysign(x, y);
 
 // Posix has demanded 'float copysignf(float, float)' (from C99) since Issue 6.
diff --git a/include/core/SkPostConfig.h b/include/core/SkPostConfig.h
index ec17b65..2d6ab44 100644
--- a/include/core/SkPostConfig.h
+++ b/include/core/SkPostConfig.h
@@ -126,10 +126,10 @@
  * Defaults to 1 in DEBUG and 0 in RELEASE.
  */
 #ifndef SK_ENABLE_INST_COUNT
-#  ifdef SK_DEBUG
 // Only enabled for static builds, because instance counting relies on static
 // variables in functions defined in header files.
-#    define SK_ENABLE_INST_COUNT !defined(SKIA_DLL)
+#  if defined(SK_DEBUG) && !defined(SKIA_DLL)
+#    define SK_ENABLE_INST_COUNT 1
 #  else
 #    define SK_ENABLE_INST_COUNT 0
 #  endif