Simplify the BackingStore handling.

This patch removes the black borders around the widget when resizing.

- No need to resize the BackingStore direcly, RenderWidgetHostImpl::WasResized
  takes care of allocating a new one with the correct size.
- Get the backing store just before painting instead of pushing it when
  scheduling an update. Getting the backing store has side effects that
  assumes it is done that way.
- Remove the about_to_validate_and_paint_ check as all our painting updates
  are scheduled back to the event loop and that we are now only fetching
  the BackingStore at this point.

1 files changed, 7 insertions, 15 deletions

diff --git a/lib/render_widget_host_view_qt_delegate_widget.cpp b/lib/render_widget_host_view_qt_delegate_widget.cpp
index 8be1d308f..9a659069f 100644
--- a/lib/render_widget_host_view_qt_delegate_widget.cpp
+++ b/lib/render_widget_host_view_qt_delegate_widget.cpp
@@ -3,13 +3,14 @@
 #include "shared/backing_store_qt.h"
 #include "shared/render_widget_host_view_qt.h"
 
+#include "content/browser/renderer_host/render_view_host_impl.h"
+
 #include <QResizeEvent>
 #include <QPaintEvent>
 
 RenderWidgetHostViewQtDelegateWidget::RenderWidgetHostViewQtDelegateWidget(content::RenderWidgetHostViewQt* view, QWidget *parent)
     : QWidget(parent)
     , m_painter(0)
-    , m_backingStore(0)
     , m_view(view)
 {
     setFocusPolicy(Qt::ClickFocus);
@@ -47,19 +48,12 @@ void RenderWidgetHostViewQtDelegateWidget::update(const QRect& rect)
     QWidget::update(rect);
 }
 
-void RenderWidgetHostViewQtDelegateWidget::setBackingStore(BackingStoreQt* backingStore)
-{
-    m_backingStore = backingStore;
-    if (m_backingStore)
-        m_backingStore->resize(size());
-}
-
 void RenderWidgetHostViewQtDelegateWidget::paintEvent(QPaintEvent * event)
 {
-    if (!m_backingStore)
-        return;
-    QPainter painter(this);
-    m_backingStore->paintToTarget(&painter, event->rect());
+    if (BackingStoreQt *backingStore = m_view->GetBackingStore()) {
+        QPainter painter(this);
+        backingStore->paintToTarget(&painter, event->rect());
+    }
 }
 
 QPainter* RenderWidgetHostViewQtDelegateWidget::painter()
@@ -71,9 +65,7 @@ QPainter* RenderWidgetHostViewQtDelegateWidget::painter()
 
 void RenderWidgetHostViewQtDelegateWidget::resizeEvent(QResizeEvent *resizeEvent)
 {
-    if (m_backingStore)
-        m_backingStore->resize(resizeEvent->size());
-    QWidget::update();
+    m_view->GetRenderWidgetHost()->WasResized();
 }
 
 bool RenderWidgetHostViewQtDelegateWidget::event(QEvent *event)