SkPdf: smaller color serialization

src/pdf/SkPDFUtils.h

Index: src/pdf/SkPDFUtils.h
diff --git a/src/pdf/SkPDFUtils.h b/src/pdf/SkPDFUtils.h
index 124e19961481a6d48da583f8a00c923fe1ef0b03..e655d9e984ed4a3b55d4038ffd53ad3ae81463bb 100644
--- a/src/pdf/SkPDFUtils.h
+++ b/src/pdf/SkPDFUtils.h
@@ -57,6 +57,15 @@ void DrawFormXObject(int objectIndex, SkWStream* content);
 void ApplyGraphicState(int objectIndex, SkWStream* content);
 void ApplyPattern(int objectIndex, SkWStream* content);
 
+// Converts (value / 255.0) with three significant digits of accuracy.
+// Writes value as string into result.  Returns strlen() of result.
+size_t ColorToDecimal(uint8_t value, char result[5]);
+inline void AppendColorComponent(uint8_t value, SkWStream* wStream) {
+    char buffer[5];
+    size_t len = SkPDFUtils::ColorToDecimal(value, buffer);
+    wStream->write(buffer, len);
+}
+
 // 3 = '-', '.', and '\0' characters.
 // 9 = number of significant digits
 // abs(FLT_MIN_10_EXP) = number of zeros in FLT_MIN