Remove include of stdlib.h from SkTypes.h.

Unfortunately, immintrin.h (which is also included by SkTypes)
includes xmmintrin.h which includes mm_malloc.h which includes
stdlib.h for malloc even though, from the implementation, it is
difficult to see why.

Fortunately, arm_neon.h does not seem to be involved in such
shenanigans, so building for Android will keep things sane.

TBR=reed@google.com
Doesn't change Skia API, just moves an include.

Review URL: https://codereview.chromium.org/1313203003
diff --git a/tests/PathOpsAngleTest.cpp b/tests/PathOpsAngleTest.cpp
index 9f9c321..cec8dde 100644
--- a/tests/PathOpsAngleTest.cpp
+++ b/tests/PathOpsAngleTest.cpp
@@ -51,7 +51,7 @@
                     float p2 = SkDoubleToScalar(line[1].fY * test.fX);
                     int p1Bits = SkFloatAs2sCompliment(p1);
                     int p2Bits = SkFloatAs2sCompliment(p2);
-                    int epsilon = abs(p1Bits - p2Bits);
+                    int epsilon = SkTAbs(p1Bits - p2Bits);
                     if (maxEpsilon < epsilon) {
                         SkDebugf("line={{0, 0}, {%1.7g, %1.7g}} t=%1.7g pt={%1.7g, %1.7g}"
                             " epsilon=%d\n",
@@ -104,7 +104,7 @@
         float p2 = SkDoubleToScalar(line[1].fY * last.fX);
         int p1Bits = SkFloatAs2sCompliment(p1);
         int p2Bits = SkFloatAs2sCompliment(p2);
-        int epsilon = abs(p1Bits - p2Bits);
+        int epsilon = SkTAbs(p1Bits - p2Bits);
         if (maxEpsilon < epsilon) {
             SkDebugf("line={{0, 0}, {%1.7g, %1.7g}} t=%1.7g/%1.7g/%1.7g moveT=%1.7g"
                     " pt={%1.7g, %1.7g} epsilon=%d\n",