cc: Make OutputSurface::Reshape abstract

cc/output/software_output_device.cc

Index: cc/output/software_output_device.cc
diff --git a/cc/output/software_output_device.cc b/cc/output/software_output_device.cc
index 449fa3075cbdf8a2fcf75a38ef5de09fd481bc50..04a426a12eac4ee497192ebb17ce36ef07f898a3 100644
--- a/cc/output/software_output_device.cc
+++ b/cc/output/software_output_device.cc
@@ -10,15 +10,11 @@
 
 namespace cc {
 
-SoftwareOutputDevice::SoftwareOutputDevice() : scale_factor_(1.f) {
-}
-
-SoftwareOutputDevice::~SoftwareOutputDevice() {}
+SoftwareOutputDevice::SoftwareOutputDevice() = default;
+SoftwareOutputDevice::~SoftwareOutputDevice() = default;
 
 void SoftwareOutputDevice::Resize(const gfx::Size& viewport_pixel_size,
                                   float scale_factor) {
-  scale_factor_ = scale_factor;
-
   if (viewport_pixel_size_ == viewport_pixel_size)
     return;