Add control of manual mipmapping to GrContextOptions

src/gpu/gl/GrGLCaps.cpp

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #include "GrGLCaps.h"
 
@@ skipping 533 matching lines @@
         }
     } else if (ctxInfo.hasExtension("GL_OES_sample_shading")) {
         fSampleShadingSupport = true;
     }
 
     // We support manual mip-map generation (via iterative downsampling draw calls). This fixes
     // bugs on some cards/drivers that produce incorrect mip-maps for sRGB textures when using
     // glGenerateMipmap. Our implementation requires mip-level sampling control. Additionally,
     // it can be much slower (especially on mobile GPUs), so we opt-in only when necessary:
     if (fMipMapLevelAndLodControlSupport &&
-        ((kIntel_GrGLVendor == ctxInfo.vendor()) ||
+        (contextOptions.fDoManualMipmapping ||
+         (kIntel_GrGLVendor == ctxInfo.vendor()) ||
          (kNVIDIA_GrGLDriver == ctxInfo.driver() && isMAC) ||
          (kATI_GrGLVendor == ctxInfo.vendor()))) {
         fDoManualMipmapping = true;
     }
 
     // Requires fTextureRedSupport, fTextureSwizzleSupport, msaa support, ES compatibility have
     // already been detected.
     this->initConfigTable(ctxInfo, gli, glslCaps);
 
     this->applyOptionsOverrides(contextOptions);
@@ skipping 1359 matching lines @@
         for (int j = 0; j < kExternalFormatUsageCnt; ++j) {
             SkASSERT(defaultEntry.fFormats.fExternalFormat[j] !=
                      fConfigTable[i].fFormats.fExternalFormat[j]);
         }
         SkASSERT(defaultEntry.fFormats.fExternalType != fConfigTable[i].fFormats.fExternalType);
     }
 #endif
 }
 
 void GrGLCaps::onApplyOptionsOverrides(const GrContextOptions& options) {}