Disable MIP mapping on PowerVR 54x. This GPU spews a lot of errors when using GenerateMipMaps.

src/gpu/gl/GrGLCaps.cpp

Index: src/gpu/gl/GrGLCaps.cpp
diff --git a/src/gpu/gl/GrGLCaps.cpp b/src/gpu/gl/GrGLCaps.cpp
index e1f3e1b0330215adf60948c7eb854f9aa172ef88..9917c1f2a839dbede67b0357ee645744cdbc2c6c 100644
--- a/src/gpu/gl/GrGLCaps.cpp
+++ b/src/gpu/gl/GrGLCaps.cpp
@@ -358,6 +358,11 @@ void GrGLCaps::init(const GrContextOptions& contextOptions,
         fMipMapSupport = fNPOTTextureTileSupport || ctxInfo.hasExtension("GL_IMG_texture_npot");
     }
 
+    // Using MIPs on this GPU seems to be a source of trouble.
+    if (kPowerVR54x_GrGLRenderer == ctxInfo.renderer()) {
+        fMipMapSupport = false;
+    }
+
     GR_GL_GetIntegerv(gli, GR_GL_MAX_TEXTURE_SIZE, &fMaxTextureSize);
     GR_GL_GetIntegerv(gli, GR_GL_MAX_RENDERBUFFER_SIZE, &fMaxRenderTargetSize);
     // Our render targets are always created with textures as the color