Make ANGLE perf decisions be runtime rather than compile time

src/gpu/gl/GrGLUtil.cpp

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #include "GrGLUtil.h"
 #include "SkMatrix.h"
@@ skipping 129 matching lines @@
             return;
         }
 
         int n = sscanf(versionString, "OpenGL ES %d.%d Mesa %d.%d",
                        &major, &minor, &driverMajor, &driverMinor);
         if (4 == n) {
             *outDriver = kMesa_GrGLDriver;
             *outVersion = GR_GL_DRIVER_VER(driverMajor, driverMinor);
             return;
         }
+        if (0 == strncmp("ANGLE", rendererString, 5)) {
+            *outDriver = kANGLE_GrGLDriver;
+            n = sscanf(versionString, "OpenGL ES %d.%d (ANGLE %d.%d", &major, &minor, &driverMajor,
+                                                                      &driverMinor);
+            if (4 == n) {
+                *outVersion = GR_GL_DRIVER_VER(driverMajor, driverMinor);
+            }
+            return;
+        }
     }
 
     if (kIntel_GrGLVendor == vendor) {
         // We presume we're on the Intel driver since it hasn't identified itself as Mesa.
         *outDriver = kIntel_GrGLDriver;
     }
 }
 
 GrGLVersion GrGLGetVersionFromString(const char* versionString) {
     if (NULL == versionString) {
@@ skipping 197 matching lines @@
     GR_STATIC_ASSERT(2 == kGreater_StencilFunc);
     GR_STATIC_ASSERT(3 == kGEqual_StencilFunc);
     GR_STATIC_ASSERT(4 == kLess_StencilFunc);
     GR_STATIC_ASSERT(5 == kLEqual_StencilFunc);
     GR_STATIC_ASSERT(6 == kEqual_StencilFunc);
     GR_STATIC_ASSERT(7 == kNotEqual_StencilFunc);
     SkASSERT((unsigned) basicFunc < kBasicStencilFuncCount);
 
     return gTable[basicFunc];
 }