sRGB support in Ganesh. Several pieces:

include/gpu/GrTypes.h

Index: include/gpu/GrTypes.h
diff --git a/include/gpu/GrTypes.h b/include/gpu/GrTypes.h
index 3def9aaa993df434948afe15cf8263d655f42776..9be500d3b2206e004a9fbed3bc176365bae51d0a 100644
--- a/include/gpu/GrTypes.h
+++ b/include/gpu/GrTypes.h
@@ -218,6 +218,10 @@ enum GrPixelConfig {
      */
     kSRGBA_8888_GrPixelConfig,
     /**
+     * Premultiplied and sRGB. Byte order is b,g,r,a.
+     */
+    kSBGRA_8888_GrPixelConfig,
+    /**
      * ETC1 Compressed Data
      */
     kETC1_GrPixelConfig,
@@ -268,8 +272,10 @@ static const int kGrPixelConfigCnt = kLast_GrPixelConfig + 1;
 #endif
 #if SK_PMCOLOR_BYTE_ORDER(B,G,R,A)
     static const GrPixelConfig kSkia8888_GrPixelConfig = kBGRA_8888_GrPixelConfig;
+    static const GrPixelConfig kSkiaGamma8888_GrPixelConfig = kSBGRA_8888_GrPixelConfig;
 #elif SK_PMCOLOR_BYTE_ORDER(R,G,B,A)
     static const GrPixelConfig kSkia8888_GrPixelConfig = kRGBA_8888_GrPixelConfig;
+    static const GrPixelConfig kSkiaGamma8888_GrPixelConfig = kSRGBA_8888_GrPixelConfig;
 #else
     #error "SK_*32_SHIFT values must correspond to GL_BGRA or GL_RGBA format."
 #endif
@@ -311,6 +317,7 @@ static inline bool GrPixelConfigIs8888(GrPixelConfig config) {
         case kRGBA_8888_GrPixelConfig:
         case kBGRA_8888_GrPixelConfig:
         case kSRGBA_8888_GrPixelConfig:
+        case kSBGRA_8888_GrPixelConfig:
             return true;
         default:
             return false;
@@ -322,6 +329,7 @@ static inline bool GrPixelConfigIs8888(GrPixelConfig config) {
 static inline bool GrPixelConfigIsSRGB(GrPixelConfig config) {
     switch (config) {
         case kSRGBA_8888_GrPixelConfig:
+        case kSBGRA_8888_GrPixelConfig:
             return true;
         default:
             return false;
@@ -336,6 +344,10 @@ static inline GrPixelConfig GrPixelConfigSwapRAndB(GrPixelConfig config) {
             return kRGBA_8888_GrPixelConfig;
         case kRGBA_8888_GrPixelConfig:
             return kBGRA_8888_GrPixelConfig;
+        case kSBGRA_8888_GrPixelConfig:
+            return kSRGBA_8888_GrPixelConfig;
+        case kSRGBA_8888_GrPixelConfig:
+            return kSBGRA_8888_GrPixelConfig;
         default:
             return kUnknown_GrPixelConfig;
     }
@@ -353,6 +365,7 @@ static inline size_t GrBytesPerPixel(GrPixelConfig config) {
         case kRGBA_8888_GrPixelConfig:
         case kBGRA_8888_GrPixelConfig:
         case kSRGBA_8888_GrPixelConfig:
+        case kSBGRA_8888_GrPixelConfig:
             return 4;
         case kRGBA_half_GrPixelConfig:
             return 8;
@@ -386,6 +399,16 @@ static inline bool GrPixelConfigIsAlphaOnly(GrPixelConfig config) {
     }
 }
 
+static inline bool GrAllowSRGBForDestinationPixelConfig(GrPixelConfig config) {
+    switch (config) {
+        case kRGBA_8888_GrPixelConfig:
+        case kBGRA_8888_GrPixelConfig:
+            return false;
+        default:
+            return true;
+    }
+}
+
 /**
  * Optional bitfield flags that can be set on GrSurfaceDesc (below).
  */