Make GrGLConfigConversionEffect work for Imagination and some other GPUs.

src/gpu/gl/GrGLUtil.cpp

Index: src/gpu/gl/GrGLUtil.cpp
diff --git a/src/gpu/gl/GrGLUtil.cpp b/src/gpu/gl/GrGLUtil.cpp
index 0fa2d2ce1882289f450ee3297727fbfdecf0dc5f..03675e132717a1ce58e3e16387f9216649572e06 100644
--- a/src/gpu/gl/GrGLUtil.cpp
+++ b/src/gpu/gl/GrGLUtil.cpp
@@ -229,6 +229,8 @@ GrGLRenderer GrGLGetRendererFromString(const char* rendererString) {
             return kTegra3_GrGLRenderer;
         } else if (0 == strcmp(rendererString, "NVIDIA Tegra")) {
             return kTegra2_GrGLRenderer;
+        } else if (0 == strcmp(rendererString, "PowerVR Rogue Hood")) {
+            return kPVRRogueHood_GrGLRenderer;
         }
     }
     return kOther_GrGLRenderer;