Fix GOOGLE3 Android build.

DebugWriteToStderr isn't defined for Android. I'm not sure if I just didn't test compiling for Android or if this is due to a change in the base library.

BUG=skia:

No public API changes.
TBR=reed@google.com

Review URL: https://codereview.chromium.org/1438773003

include/core/SkPostConfig.h

@@ -147,16 +147,20 @@
 #
 #endif
 
+#if defined(GOOGLE3)
+    // Used as argument to DumpStackTrace in SK_ALWAYSBREAK.
+    void SkDebugfForDumpStackTrace(const char* data, void* unused);
+#endif
+
 #ifndef SK_ALWAYSBREAK
 #  if defined(GOOGLE3)
-     void DebugWriteToStderr(const char*, void*);
      void DumpStackTrace(int skip_count, void w(const char*, void*),
                          void* arg);
 #    define SK_ALWAYSBREAK(cond) do { \
               if (cond) break; \
               SkNO_RETURN_HINT(); \
               SkDebugf("%s:%d: failed assertion \"%s\"\n", __FILE__, __LINE__, #cond); \
-              DumpStackTrace(0, DebugWriteToStderr, nullptr); \
+              DumpStackTrace(0, SkDebugfForDumpStackTrace, nullptr); \
               SK_CRASH(); \
         } while (false)
 #  elif defined(SK_DEBUG)

src/core/SkDebug.cpp

@@ -57,3 +57,9 @@ size_t SkToSizeT(uintmax_t x) {
 }
 
 #endif
+
+#if defined(GOOGLE3)
+void SkDebugfForDumpStackTrace(const char* data, void* unused) {
+    SkDebugf("%s", data);
+}
+#endif