* Electron Version: 2.0.0
* Operating System (Platform and Version): Windows 10
* Last known working Electron version: before commit bb5eecc16cff8053c7b04e0b9396803fbbb8c4df

**Expected Behavior**
Width and height of a window should not change while being dragged 

**Actual behavior**
Width and height become smaller.

**To Reproduce**
Create a window with:
  var mainWindow = new BrowserWindow({width: 1024, height: 880, x: 30, y: 30,
            resizable: false })

Then drag the window.  Width and height become smaller than specified (1024, 880)

**Additional Information**
NativeWindowViews::SetBounds calls SetMin/MaxSize(bounds) when resizable_ is false.  bounds get adjusted to smaller  numbers by WindowBoundsToContentBounds.

shell/browser/native_window_views.cc
size = ContentBoundsToWindowBounds(gfx::Rect(size)).size();
  widget()->CenterWindow(size);
#if defined(OS_WIN)
  
  if (fullscreen)
    last_window_state_ = ui::SHOW_STATE_FULLSCREEN;
  else
    last_window_state_ = ui::SHOW_STATE_NORMAL;
  last_normal_bounds_ = GetBounds();
#endif
#if defined(OS_LINUX)
  
  aura::Window* window = GetNativeWindow();
  if (window)
    window->AddPreTargetHandler(this);
#endif
}
NativeWindowViews::~NativeWindowViews() {
  widget()->RemoveObserver(this);
#if defined(OS_WIN)
  
  SetForwardMouseMessages(false);
#endif
#if defined(OS_LINUX)
  aura::Window* window = GetNativeWindow();
  if (window)
    window->RemovePreTargetHandler(this);
#endif
}
void NativeWindowViews::SetContentView(views::View* view) {