expand unitests for color4f

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1622893002

TBR=

Review URL: https://codereview.chromium.org/1622893002

3 files changed, 10 insertions, 0 deletions

diff --git a/include/core/SkColor.h b/include/core/SkColor.h
index f18fb7ee5e..3ebd18b7aa 100644
--- a/include/core/SkColor.h
+++ b/include/core/SkColor.h
@@ -169,6 +169,8 @@ struct SkPM4f {
     float fVec[4];
 
     float a() const { return fVec[SK_A32_SHIFT/8]; }
+
+    static SkPM4f FromPMColor(SkPMColor);
 };
 
 /*
diff --git a/include/core/SkColorFilter.h b/include/core/SkColorFilter.h
index 211aae6962..aece22e05a 100644
--- a/include/core/SkColorFilter.h
+++ b/include/core/SkColorFilter.h
@@ -81,6 +81,10 @@ public:
     */
     virtual uint32_t getFlags() const { return 0; }
 
+    bool supports4f() const {
+        return SkToBool(this->getFlags() & kSupports4f_Flag);
+    }
+
     /**
      *  If this subclass can optimally createa composition with the inner filter, return it as
      *  a new filter (which the caller must unref() when it is done). If no such optimization
diff --git a/include/core/SkShader.h b/include/core/SkShader.h
index bf6d6ddb42..297091d542 100644
--- a/include/core/SkShader.h
+++ b/include/core/SkShader.h
@@ -121,6 +121,10 @@ public:
          */
         virtual uint32_t getFlags() const { return 0; }
 
+        bool supports4f() const {
+            return SkToBool(this->getFlags() & kSupports4f_Flag);
+        }
+
         /**
          *  Called for each span of the object being drawn. Your subclass should
          *  set the appropriate colors (with premultiplied alpha) that correspond