Add stencil-only clear bug workaround back but for all devices.

src/gpu/gl/GrGLGpu.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 "GrGLGpu.h"
 #include "GrGLStencilBuffer.h"
@@ skipping 1185 matching lines @@
                 GL_CALL(FramebufferRenderbuffer(GR_GL_FRAMEBUFFER,
                                                 GR_GL_STENCIL_ATTACHMENT,
                                                 GR_GL_RENDERBUFFER, sbDesc.fRenderbufferID));
                 if (sFmt.fPacked) {
                     GL_CALL(FramebufferRenderbuffer(GR_GL_FRAMEBUFFER,
                                                     GR_GL_DEPTH_ATTACHMENT,
                                                     GR_GL_RENDERBUFFER, sbDesc.fRenderbufferID));
                 }
 
                 GL_CALL(ClearStencil(0));
+                // Many GL implementations seem to have trouble with clearing an FBO with only
+                // a stencil buffer.
+                GrGLuint tempRB;
+                GL_CALL(GenRenderbuffers(1, &tempRB));
+                GL_CALL(BindRenderbuffer(GR_GL_RENDERBUFFER, tempRB));
+                GL_CALL(RenderbufferStorage(GR_GL_RENDERBUFFER, GR_GL_RGBA8, width, height));
+                GL_CALL(FramebufferRenderbuffer(GR_GL_FRAMEBUFFER,
+                                                GR_GL_COLOR_ATTACHMENT0,
+                                                GR_GL_RENDERBUFFER, tempRB));
+
                 GL_CALL(Clear(GR_GL_STENCIL_BUFFER_BIT));
 
+                GL_CALL(FramebufferRenderbuffer(GR_GL_FRAMEBUFFER,
+                                                GR_GL_COLOR_ATTACHMENT0,
+                                                GR_GL_RENDERBUFFER, 0));
+                GL_CALL(DeleteRenderbuffers(1, &tempRB));
+
                 // Unbind the SB from the FBO so that we don't keep it alive.
                 GL_CALL(FramebufferRenderbuffer(GR_GL_FRAMEBUFFER,
                                                 GR_GL_STENCIL_ATTACHMENT,
                                                 GR_GL_RENDERBUFFER, 0));
                 if (sFmt.fPacked) {
                     GL_CALL(FramebufferRenderbuffer(GR_GL_FRAMEBUFFER,
                                                     GR_GL_DEPTH_ATTACHMENT,
                                                     GR_GL_RENDERBUFFER, 0));
                 }
 
@@ skipping 1578 matching lines @@
             this->setVertexArrayID(gpu, 0);
         }
         int attrCount = gpu->glCaps().maxVertexAttributes();
         if (fDefaultVertexArrayAttribState.count() != attrCount) {
             fDefaultVertexArrayAttribState.resize(attrCount);
         }
         attribState = &fDefaultVertexArrayAttribState;
     }
     return attribState;
 }