Disable SRGB support on PowerVR Rogue due to SRGBReadWritePixels failure

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 188 matching lines @@
             srgbSupport = true;
         } else if (ctxInfo.hasExtension("GL_EXT_texture_sRGB")) {
             if (ctxInfo.hasExtension("GL_ARB_framebuffer_sRGB") ||
                 ctxInfo.hasExtension("GL_EXT_framebuffer_sRGB")) {
                 srgbSupport = true;
             }
          }
         // All the above srgb extensions support toggling srgb writes
         fSRGBWriteControl = srgbSupport;
     } else {
-        srgbSupport = ctxInfo.version() >= GR_GL_VER(3,0) ||
-                      ctxInfo.hasExtension("GL_EXT_sRGB");
+        // See http://skbug.com/4148 for PowerVR issue.
+        srgbSupport = kPowerVRRogue_GrGLRenderer != ctxInfo.renderer() &&
+                      (ctxInfo.version() >= GR_GL_VER(3,0) || ctxInfo.hasExtension("GL_EXT_sRGB"));
         // ES through 3.1 requires EXT_srgb_write_control to support toggling
         // sRGB writing for destinations.
         fSRGBWriteControl = ctxInfo.hasExtension("GL_EXT_sRGB_write_control");
     }
 
     // Frag Coords Convention support is not part of ES
     // Known issue on at least some Intel platforms:
     // http://code.google.com/p/skia/issues/detail?id=946
     if (kIntel_GrGLVendor != ctxInfo.vendor() && kGLES_GrGLStandard != standard) {
         fFragCoordsConventionSupport = ctxInfo.glslGeneration() >= k150_GrGLSLGeneration ||
@@ skipping 985 matching lines @@
         for (int p = 0; p < kGrSLPrecisionCount; ++p) {
             glslCaps->fFloatPrecisions[kGeometry_GrShaderType][p] = 
                                                glslCaps->fFloatPrecisions[kVertex_GrShaderType][p];
         }
     }
 }