Have gpu createTestingOlyBackendTexture know if it is a render target or not

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 "GrGLBuffer.h"
 #include "GrGLGLSL.h"
@@ skipping 4514 matching lines @@
         case kBlend_GrXferBarrierType:
             SkASSERT(GrCaps::kAdvanced_BlendEquationSupport ==
                      this->caps()->blendEquationSupport());
             GL_CALL(BlendBarrier());
             return;
         default: break; // placate compiler warnings that kNone not handled
     }
 }
 
 GrBackendObject GrGLGpu::createTestingOnlyBackendTexture(void* pixels, int w, int h,
-                                                         GrPixelConfig config) {
+                                                         GrPixelConfig config, bool /*isRT*/) {
     if (!this->caps()->isConfigTexturable(config)) {
         return false;
     }
     GrGLTextureInfo* info = new GrGLTextureInfo;
     info->fTarget = GR_GL_TEXTURE_2D;
     info->fID = 0;
     GL_CALL(GenTextures(1, &info->fID));
     GL_CALL(ActiveTexture(GR_GL_TEXTURE0));
     GL_CALL(PixelStorei(GR_GL_UNPACK_ALIGNMENT, 1));
     GL_CALL(BindTexture(info->fTarget, info->fID));
@@ skipping 105 matching lines @@
         if (GR_GL_TEXTURE_EXTERNAL == glTexture->target() ||
             GR_GL_TEXTURE_RECTANGLE == glTexture->target()) {
             copyParams->fFilter = GrTextureParams::kNone_FilterMode;
             copyParams->fWidth = texture->width();
             copyParams->fHeight = texture->height();
             return true;
         }
     }
     return false;
 }