Make code compile with clang_use_chrome_plugin (part VI)

This change mainly contains files in xfa/fwl directory.
This is part of the efforts to make PDFium code compilable
by Clang chromium style plugins.

The changes are mainly the following:
-- move inline constructor/destructor of complex class/struct out-of-line;
-- add constructor/destructor of complex class/struct if not
 explicitly defined;
-- add explicit out-of-line copy constructor when needed;
-- move inline virtual functions out-of-line;
-- Properly mark virtual functions with 'override';
-- some minor cleanups;

BUG=pdfium:469

Review-Url: https://codereview.chromium.org/2070583003

1 files changed, 14 insertions, 0 deletions

diff --git a/xfa/fwl/lightwidget/cfwl_widgetproperties.cpp b/xfa/fwl/lightwidget/cfwl_widgetproperties.cpp
index 9afa1b6959..31e1dda687 100644
--- a/xfa/fwl/lightwidget/cfwl_widgetproperties.cpp
+++ b/xfa/fwl/lightwidget/cfwl_widgetproperties.cpp
@@ -8,6 +8,20 @@
 
 #include "xfa/fwl/lightwidget/cfwl_widget.h"
 
+CFWL_WidgetProperties::CFWL_WidgetProperties()
+    : m_dwStyles(FWL_WGTSTYLE_Child),
+      m_dwStyleExes(0),
+      m_dwStates(0),
+      m_pParent(nullptr),
+      m_pOwner(nullptr) {
+  m_rtWidget.Set(0, 0, 0, 0);
+}
+
+CFWL_WidgetProperties::~CFWL_WidgetProperties() {}
+
+CFWL_WidgetProperties::CFWL_WidgetProperties(
+    const CFWL_WidgetProperties& other) = default;
+
 CFWL_WidgetImpProperties CFWL_WidgetProperties::MakeWidgetImpProperties(
     IFWL_DataProvider* pDataProvider) const {
   CFWL_WidgetImpProperties result;