[qcms] Make half float code self-contained: add halffloat.h

third_party/qcms/src/transform_util.h

Index: third_party/qcms/src/transform_util.h
diff --git a/third_party/qcms/src/transform_util.h b/third_party/qcms/src/transform_util.h
index 7fb9baf272767483761ed381be611e8d23f9e8fd..44ff63ec8f0a87e3c914d1a94e32e9875b58db77 100644
--- a/third_party/qcms/src/transform_util.h
+++ b/third_party/qcms/src/transform_util.h
@@ -55,17 +55,4 @@ void build_output_lut(struct curveType *trc,
 struct matrix matrix_invert(struct matrix mat);
 qcms_bool compute_precache(struct curveType *trc, uint8_t *output);
 
-static inline unsigned short float_to_half_float(float f)
-{
-	extern const unsigned short qcms_half_float_base_table[512];
-	extern const unsigned char qcms_half_float_shift_table[512];
-
-	// See Blink::Source/platform/graphics/gpu/WebGLImageConversion.cpp::convertFloatToHalfFloat()
-	// and http://crbug.com/491784
-
-	unsigned temp = *((unsigned *)(&f));
-	unsigned signexp = (temp >> 23) & 0x1ff;
-	return qcms_half_float_base_table[signexp] + ((temp & 0x007fffff) >> qcms_half_float_shift_table[signexp]);
-}
-
 #endif