[Remoting Client] Fix scaling bug in ViewMatrix

remoting/client/view_matrix.cc

 // Copyright 2017 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/view_matrix.h"
 
 namespace remoting {
 
 ViewMatrix::ViewMatrix() : ViewMatrix(0.f, {0.f, 0.f}) {}
 
@@ skipping 17 matching lines @@
 void ViewMatrix::SetScale(float scale) {
   scale_ = scale;
 }
 
 float ViewMatrix::GetScale() const {
   return scale_;
 }
 
 void ViewMatrix::PostScale(const Point& pivot, float scale) {
   scale_ *= scale;
+  offset_.x *= scale;
   offset_.x += (1.f - scale) * pivot.x;
+  offset_.y *= scale;
   offset_.y += (1.f - scale) * pivot.y;
 }
 
 void ViewMatrix::PostTranslate(const Vector2D& delta) {
   offset_.x += delta.x;
   offset_.y += delta.y;
 }
 
 ViewMatrix ViewMatrix::Invert() const {
   return ViewMatrix(1.f / scale_, {-offset_.x / scale_, -offset_.y / scale_});
 }
 
 std::array<float, 9> ViewMatrix::ToMatrixArray() const {
   return {{scale_, 0, offset_.x,  // Row 1
            0, scale_, offset_.y,  // Row 2
            0, 0, 1}};
 }
 
 bool ViewMatrix::IsEmpty() const {
   return scale_ == 0.f && offset_.x == 0.f && offset_.y == 0.f;
 }
 
 }  // namespace remoting