Create a separate src for colorspace tests

dm/DM.cpp

Index: dm/DM.cpp
diff --git a/dm/DM.cpp b/dm/DM.cpp
index fcc3c552eac3442efc7482857f397a1f51bed943..bf80c863ba6b2238107dfef3d9d938bf75ea48af 100644
--- a/dm/DM.cpp
+++ b/dm/DM.cpp
@@ -763,22 +763,22 @@ static bool gather_srcs() {
     for (auto colorImage : colorImages) {
         ColorCodecSrc* src = new ColorCodecSrc(colorImage, ColorCodecSrc::kBaseline_Mode,
                                                kN32_SkColorType);
-        push_src("image", "color_codec_baseline", src);
+        push_src("colorImage", "color_codec_baseline", src);
 
         src = new ColorCodecSrc(colorImage, ColorCodecSrc::kDst_HPZR30w_Mode, kN32_SkColorType);
-        push_src("image", "color_codec_HPZR30w", src);
+        push_src("colorImage", "color_codec_HPZR30w", src);
         // TODO (msarett):
         // Should we test this Dst in F16 mode (even though the Dst gamma is 2.2 instead of sRGB)?
 
         src = new ColorCodecSrc(colorImage, ColorCodecSrc::kDst_sRGB_Mode, kN32_SkColorType);
-        push_src("image", "color_codec_sRGB_kN32", src);
+        push_src("colorImage", "color_codec_sRGB_kN32", src);
         src = new ColorCodecSrc(colorImage, ColorCodecSrc::kDst_sRGB_Mode, kRGBA_F16_SkColorType);
-        push_src("image", "color_codec_sRGB_kF16", src);
+        push_src("colorImage", "color_codec_sRGB_kF16", src);
 
 #if defined(SK_TEST_QCMS)
         src = new ColorCodecSrc(colorImage, ColorCodecSrc::kQCMS_HPZR30w_Mode,
                                 kRGBA_8888_SkColorType);
-        push_src("image", "color_codec_QCMS_HPZR30w", src);
+        push_src("colorImage", "color_codec_QCMS_HPZR30w", src);
 #endif
     }