Revert of Gamma correction for distance field text.

src/core/SkPaint.cpp

Index: src/core/SkPaint.cpp
diff --git a/src/core/SkPaint.cpp b/src/core/SkPaint.cpp
index b08b2c6da7471ebc72d5447b6f44f6ad6162d45e..78d947020b20442ac8bafcc63f14d752bf2f0c83 100644
--- a/src/core/SkPaint.cpp
+++ b/src/core/SkPaint.cpp
@@ -1814,8 +1814,10 @@
 
 /*
  *  ignoreGamma tells us that the caller just wants metrics that are unaffected
- *  by gamma correction, so we set the rec to ignore preblend: i.e. gamma = 1,
- *  contrast = 0, luminanceColor = transparent black.
+ *  by gamma correction, so we jam the luminance field to 0 (most common value
+ *  for black text) in hopes that we get a cache hit easier. A better solution
+ *  would be for the fontcache lookup to know to ignore the luminance field
+ *  entirely, but not sure how to do that and keep it fast.
  */
 void SkPaint::descriptorProc(const SkDeviceProperties* deviceProperties,
                              const SkMatrix* deviceMatrix,
@@ -1825,7 +1827,7 @@
 
     SkScalerContext::MakeRec(*this, deviceProperties, deviceMatrix, &rec);
     if (ignoreGamma) {
-        rec.ignorePreBlend();
+        rec.setLuminanceColor(0);
     }
 
     size_t          descSize = sizeof(rec);
@@ -1949,10 +1951,9 @@
 }
 
 SkGlyphCache* SkPaint::detachCache(const SkDeviceProperties* deviceProperties,
-                                   const SkMatrix* deviceMatrix,
-                                   bool ignoreGamma) const {
+                                   const SkMatrix* deviceMatrix) const {
     SkGlyphCache* cache;
-    this->descriptorProc(deviceProperties, deviceMatrix, DetachDescProc, &cache, ignoreGamma);
+    this->descriptorProc(deviceProperties, deviceMatrix, DetachDescProc, &cache, false);
     return cache;
 }
 
@@ -1967,33 +1968,6 @@
                                                    rec.getDeviceGamma());
     return maskGamma.preBlend(rec.getLuminanceColor());
 }
-
-size_t SkScalerContext::GetGammaLUTSize(SkScalar contrast, SkScalar paintGamma,
-                                        SkScalar deviceGamma, int* width, int* height) {
-    SkAutoMutexAcquire ama(gMaskGammaCacheMutex);
-    const SkMaskGamma& maskGamma = cachedMaskGamma(contrast,
-                                                   paintGamma,
-                                                   deviceGamma);
-
-    maskGamma.getGammaTableDimensions(width, height);
-    size_t size = (*width)*(*height)*sizeof(uint8_t);
-
-    return size;
-}
-
-void SkScalerContext::GetGammaLUTData(SkScalar contrast, SkScalar paintGamma, SkScalar deviceGamma,
-                                      void* data) {
-    SkAutoMutexAcquire ama(gMaskGammaCacheMutex);
-    const SkMaskGamma& maskGamma = cachedMaskGamma(contrast,
-                                                   paintGamma,
-                                                   deviceGamma);
-    int width, height;
-    maskGamma.getGammaTableDimensions(&width, &height);
-    size_t size = width*height*sizeof(uint8_t);
-    const uint8_t* gammaTables = maskGamma.getGammaTables();
-    memcpy(data, gammaTables, size);
-}
-
 
 ///////////////////////////////////////////////////////////////////////////////
 
@@ -2583,7 +2557,7 @@
         fPaint.setPathEffect(NULL);
     }
 
-    fCache = fPaint.detachCache(NULL, NULL, false);
+    fCache = fPaint.detachCache(NULL, NULL);
 
     SkPaint::Style  style = SkPaint::kFill_Style;
     SkPathEffect*   pe = NULL;