Remove version checks for _MSC_VER < 1800 (msvs2013).

src/effects/gradients/SkLinearGradient.cpp

Index: src/effects/gradients/SkLinearGradient.cpp
diff --git a/src/effects/gradients/SkLinearGradient.cpp b/src/effects/gradients/SkLinearGradient.cpp
index 8ad120991d5176c64fb2439dc823eb76082a48a0..0a2b1581d59c4828e4f973a0ff108fc53717de28 100644
--- a/src/effects/gradients/SkLinearGradient.cpp
+++ b/src/effects/gradients/SkLinearGradient.cpp
@@ -17,12 +17,6 @@ static inline int repeat_8bits(int x) {
     return x & 0xFF;
 }
 
-// Visual Studio 2010 (MSC_VER=1600) optimizes bit-shift code incorrectly.
-// See http://code.google.com/p/skia/issues/detail?id=472
-#if defined(_MSC_VER) && (_MSC_VER >= 1600)

[mtklein, 2016/03/10 17:37:48]

ditto

-#pragma optimize("", off)
-#endif
-
 static inline int mirror_8bits(int x) {
     if (x & 256) {
         x = ~x;
@@ -30,10 +24,6 @@ static inline int mirror_8bits(int x) {
     return x & 255;
 }
 
-#if defined(_MSC_VER) && (_MSC_VER >= 1600)
-#pragma optimize("", on)
-#endif
-
 static SkMatrix pts_to_unit_matrix(const SkPoint pts[2]) {
     SkVector    vec = pts[1] - pts[0];
     SkScalar    mag = vec.length();