Make ANGLE perf decisions be runtime rather than compile time

include/gpu/gl/GrGLConfig_chrome.h

 
 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 #ifndef GrGLConfig_chrome_DEFINED
 #define GrGLConfig_chrome_DEFINED
 
 // glGetError() forces a sync with gpu process on chrome
 #define GR_GL_CHECK_ERROR_START                     0
 
-#if defined(SK_BUILD_FOR_WIN32)
-// For RGBA teximage/readpixels ANGLE will sw-convert to/from BGRA.
-#define GR_GL_RGBA_8888_PIXEL_OPS_SLOW              1
-
-// ANGLE can go faster if the entire fbo is read rather than a subrect
-#define GR_GL_FULL_READPIXELS_FASTER_THAN_PARTIAL   1
-#else
-#define GR_GL_RGBA_8888_PIXEL_OPS_SLOW              0
-#define GR_GL_FULL_READPIXELS_FASTER_THAN_PARTIAL   0
-#endif
-
 // cmd buffer allocates memory and memsets it to zero when it sees glBufferData
 // with NULL.
 #define GR_GL_USE_BUFFER_DATA_NULL_HINT             0
 
 // chrome uses this to set the context on each GL call.
 #define GR_GL_PER_GL_FUNC_CALLBACK                  1
 
 // Check error is even more expensive in chrome (cmd buffer flush). The
 // compositor also doesn't check its allocations.
 #define GR_GL_CHECK_ALLOC_WITH_GET_ERROR            0
 
 // CheckFramebufferStatus in chrome synchronizes the gpu and renderer processes.
 #define GR_GL_CHECK_FBO_STATUS_ONCE_PER_FORMAT      1
 
 // Non-VBO vertices and indices are not allowed in Chromium.
 #define GR_GL_MUST_USE_VBO                          1
 
 // Use updated Khronos signature for glShaderSource
 // (const char* const instead of char**).
 #define GR_GL_USE_NEW_SHADER_SOURCE_SIGNATURE       1
 
 #if !defined(GR_GL_IGNORE_ES3_MSAA)
     #define GR_GL_IGNORE_ES3_MSAA 1
 #endif
 
 #endif