Change device factories to take SkImageInfo instead of SkBitmap::Config

src/gpu/SkGr.cpp

Index: src/gpu/SkGr.cpp
diff --git a/src/gpu/SkGr.cpp b/src/gpu/SkGr.cpp
index fa9fa713269f87d0f7766c6f93e1b8179af4bd30..c053e8b81102e796ceb4b3442c85269021730d3c 100644
--- a/src/gpu/SkGr.cpp
+++ b/src/gpu/SkGr.cpp
@@ -260,6 +260,29 @@ GrPixelConfig SkBitmapConfig2GrPixelConfig(SkBitmap::Config config) {
     }
 }
 
+// alphatype is ignore for now, but if GrPixelConfig is expanded to encompass
+// alpha info, that will be considered.
+GrPixelConfig SkImageInfo2GrPixelConfig(SkColorType ct, SkAlphaType) {
+    switch (ct) {
+        case kUnknown_SkColorType:
+            return kUnknown_GrPixelConfig;
+        case kAlpha_8_SkColorType:
+            return kAlpha_8_GrPixelConfig;
+        case kRGB_565_SkColorType:
+            return kRGB_565_GrPixelConfig;
+        case kARGB_4444_SkColorType:
+            return kRGBA_4444_GrPixelConfig;
+        case kRGBA_8888_SkColorType:
+            return kRGBA_8888_GrPixelConfig;
+        case kBGRA_8888_SkColorType:
+            return kBGRA_8888_GrPixelConfig;
+        case kIndex_8_SkColorType:
+            return kIndex_8_GrPixelConfig;
+    }
+    SkASSERT(0);    // shouldn't get here
+    return kUnknown_GrPixelConfig;
+}
+
 bool GrPixelConfig2ColorType(GrPixelConfig config, SkColorType* ctOut) {
     SkColorType ct;
     switch (config) {