respect srgb gamma when building mips

src/gpu/SkGr.cpp

 /*
  * Copyright 2010 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #include "SkGr.h"
 #include "SkGrPriv.h"
@@ skipping 326 matching lines @@
         if (texture) {
             return texture;
         }
     }
 
     sk_sp<GrTexture> texture(create_texture_from_yuv(ctx, bitmap, desc));
     if (texture) {
         return texture.release();
     }
 
-    // SkMipMap::Build doesn't handle sRGB data correctly (yet).
-    // Failover to the GL code-path for now.
-    if (kLinear_SkColorProfileType != bitmap.profileType()) {
-        return nullptr;
+    SkMipMap::SrcGammaMode mode = SkMipMap::kRespect_SrcGammaMode;
+    if (/* we're in compatibility-mode-for-L32*/true) {
+        mode = SkMipMap::kIgnore_SrcGammaMode;
     }
 
     SkASSERT(sizeof(int) <= sizeof(uint32_t));
     if (bitmap.width() < 0 || bitmap.height() < 0) {
         return nullptr;
     }
 
     SkAutoPixmapUnlock srcUnlocker;
     if (!bitmap.requestLock(&srcUnlocker)) {
         return nullptr;
     }
     const SkPixmap& pixmap = srcUnlocker.pixmap();
     // Try to catch where we might have returned nullptr for src crbug.com/492818
     if (nullptr == pixmap.addr()) {
         sk_throw();
     }
 
-    SkAutoTDelete<SkMipMap> mipmaps(SkMipMap::Build(pixmap, nullptr));
+    SkAutoTDelete<SkMipMap> mipmaps(SkMipMap::Build(pixmap, mode, nullptr));
     if (!mipmaps) {
         return nullptr;
     }
 
     const int mipLevelCount = mipmaps->countLevels() + 1;
     if (mipLevelCount < 1) {
         return nullptr;
     }
 
     const bool isMipMapped = mipLevelCount > 1;
@@ skipping 380 matching lines @@
             SkErrorInternals::SetError( kInvalidPaint_SkError,
                                         "Sorry, I don't understand the filtering "
                                         "mode you asked for.  Falling back to "
                                         "MIPMaps.");
             textureFilterMode = GrTextureParams::kMipMap_FilterMode;
             break;
 
     }
     return textureFilterMode;
 }