[CRD iOS] Some fixes for rendering

remoting/client/display/gl_canvas.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "remoting/client/display/gl_canvas.h"
 
 #include "base/logging.h"
 #include "remoting/client/display/gl_helpers.h"
 #include "remoting/client/display/gl_math.h"
 
@@ skipping 101 matching lines @@
   DCHECK(thread_checker_.CalledOnValidThread());
   std::array<float, 9> transposed_matrix = matrix;
   TransposeTransformationMatrix(&transposed_matrix);
   glUniformMatrix3fv(transform_location_, 1, GL_FALSE,
                      transposed_matrix.data());
   transformation_set_ = true;
 }
 
 void GlCanvas::SetViewSize(int width, int height) {
   DCHECK(width > 0 && height > 0);
-  glViewport(0, 0, width, height);
   float view_size[2]{width, height};
   glUniform2fv(view_size_location_, 1, view_size);
   view_size_set_ = true;
 }
 
 void GlCanvas::DrawTexture(int texture_id,
                            int texture_handle,
                            int vertex_buffer,
                            float alpha_multiplier) {
   DCHECK(thread_checker_.CalledOnValidThread());
@@ skipping 23 matching lines @@
 int GlCanvas::GetMaxTextureSize() const {
   return max_texture_size_;
 }
 
 base::WeakPtr<Canvas> GlCanvas::GetWeakPtr() {
   DCHECK(thread_checker_.CalledOnValidThread());
   return weak_factory_.GetWeakPtr();
 }
 
 }  // namespace remoting