Use texture size to determine precision of texture coord varyings

src/gpu/gl/GrGLUtil.h

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrGLUtil_DEFINED
 #define GrGLUtil_DEFINED
 
@@ skipping 53 matching lines @@
     do {                                                                       \
         *(p) = GR_GL_INIT_ZERO;                                                \
         GR_GL_CALL(gl, GetFramebufferAttachmentParameteriv(t, a, pname, p));   \
     } while (0)
 
 #define GR_GL_GetRenderbufferParameteriv(gl, t, pname, p)                      \
     do {                                                                       \
         *(p) = GR_GL_INIT_ZERO;                                                \
         GR_GL_CALL(gl, GetRenderbufferParameteriv(t, pname, p));               \
     } while (0)
+
 #define GR_GL_GetTexLevelParameteriv(gl, t, l, pname, p)                       \
     do {                                                                       \
         *(p) = GR_GL_INIT_ZERO;                                                \
         GR_GL_CALL(gl, GetTexLevelParameteriv(t, l, pname, p));                \
     } while (0)
 
+#define GR_GL_GetShaderPrecisionFormat(gl, st, pt, range, precision)           \
+    do {                                                                       \
+        (range)[0] = GR_GL_INIT_ZERO;                                          \
+        (range)[1] = GR_GL_INIT_ZERO;                                          \
+        (*precision) = GR_GL_INIT_ZERO;                                        \
+        GR_GL_CALL(gl, GetShaderPrecisionFormat(st, pt, range, precision));    \
+    } while (0)
+
 ////////////////////////////////////////////////////////////////////////////////
 
 /**
  * Helpers for glGetString()
  */
 
 // these variants assume caller already has a string from glGetString()
 GrGLVersion GrGLGetVersionFromString(const char* versionString);
 GrGLStandard GrGLGetStandardInUseFromString(const char* versionString);
 GrGLSLVersion GrGLGetGLSLVersionFromString(const char* versionString);
@@ skipping 90 matching lines @@
         GR_GL_LOG_CALLS_IMPL(X);                                \
     } while (false)
 
 // call glGetError without doing a redundant error check or logging.
 #define GR_GL_GET_ERROR(IFACE) (IFACE)->fFunctions.fGetError()
 
 GrGLenum GrToGLStencilFunc(GrStencilFunc basicFunc);
 
 
 #endif