Include scaler context flags (gamma and contrast boost) in the text blob cache key.

src/gpu/text/GrAtlasTextContext.cpp

Index: src/gpu/text/GrAtlasTextContext.cpp
diff --git a/src/gpu/text/GrAtlasTextContext.cpp b/src/gpu/text/GrAtlasTextContext.cpp
index 22fd8a35811438b086ebc9869a7e113ffe3f5ac3..ff62b1f9c51feeac63e946a67988e3f8c2403d13 100644
--- a/src/gpu/text/GrAtlasTextContext.cpp
+++ b/src/gpu/text/GrAtlasTextContext.cpp
@@ -96,6 +96,7 @@ void GrAtlasTextContext::drawTextBlob(GrContext* context, GrDrawContext* dc,
     bool canCache = !(skPaint.getPathEffect() ||
                       (mf && !mf->asABlur(&blurRec)) ||
                       drawFilter);
+    uint32_t scalerContextFlags = ComputeScalerContextFlags(dc);
 
     GrTextBlobCache* cache = context->getTextBlobCache();
     if (canCache) {
@@ -116,6 +117,7 @@ void GrAtlasTextContext::drawTextBlob(GrContext* context, GrDrawContext* dc,
         key.fStyle = skPaint.getStyle();
         key.fHasBlur = SkToBool(mf);
         key.fCanonicalColor = canonicalColor;
+        key.fScalerContextFlags = scalerContextFlags;
         cacheBlob.reset(SkSafeRef(cache->find(key)));
     }
 
@@ -126,8 +128,6 @@ void GrAtlasTextContext::drawTextBlob(GrContext* context, GrDrawContext* dc,
         return;
     }
 
-    uint32_t scalerContextFlags = ComputeScalerContextFlags(dc);
-
     if (cacheBlob) {
         if (cacheBlob->mustRegenerate(skPaint, grPaint.getColor(), blurRec, viewMatrix, x, y)) {
             // We have to remake the blob because changes may invalidate our masks.