Use refs for non-null GraphicsContext, Scrollbar, etc. in scrollbar related code

third_party/WebKit/Source/platform/exported/WebScrollbarThemeClientImpl.cpp

Index: third_party/WebKit/Source/platform/exported/WebScrollbarThemeClientImpl.cpp
diff --git a/third_party/WebKit/Source/platform/exported/WebScrollbarThemeClientImpl.cpp b/third_party/WebKit/Source/platform/exported/WebScrollbarThemeClientImpl.cpp
index 5d0b0106945516d84ca55b87eae49a888b174f35..6c7513b1f38e191d7c165b9fd95405fb4576456c 100644
--- a/third_party/WebKit/Source/platform/exported/WebScrollbarThemeClientImpl.cpp
+++ b/third_party/WebKit/Source/platform/exported/WebScrollbarThemeClientImpl.cpp
@@ -31,15 +31,15 @@
 
 namespace blink {
 
-WebScrollbarThemeClientImpl::WebScrollbarThemeClientImpl(WebScrollbar* scrollbar)
+WebScrollbarThemeClientImpl::WebScrollbarThemeClientImpl(WebScrollbar& scrollbar)
     : m_scrollbar(scrollbar)
 {
-    ScrollbarTheme::theme()->registerScrollbar(this);
+    ScrollbarTheme::theme().registerScrollbar(*this);
 }
 
 WebScrollbarThemeClientImpl::~WebScrollbarThemeClientImpl()
 {
-    ScrollbarTheme::theme()->unregisterScrollbar(this);
+    ScrollbarTheme::theme().unregisterScrollbar(*this);
 }
 
 int WebScrollbarThemeClientImpl::x() const
@@ -64,12 +64,12 @@ int WebScrollbarThemeClientImpl::height() const
 
 IntSize WebScrollbarThemeClientImpl::size() const
 {
-    return m_scrollbar->size();
+    return m_scrollbar.size();
 }
 
 IntPoint WebScrollbarThemeClientImpl::location() const
 {
-    return m_scrollbar->location();
+    return m_scrollbar.location();
 }
 
 Widget* WebScrollbarThemeClientImpl::parent() const
@@ -111,13 +111,13 @@ void WebScrollbarThemeClientImpl::invalidateRect(const IntRect&)
 
 ScrollbarOverlayStyle WebScrollbarThemeClientImpl::scrollbarOverlayStyle() const
 {
-    return static_cast<ScrollbarOverlayStyle>(m_scrollbar->scrollbarOverlayStyle());
+    return static_cast<ScrollbarOverlayStyle>(m_scrollbar.scrollbarOverlayStyle());
 }
 
 void WebScrollbarThemeClientImpl::getTickmarks(Vector<IntRect>& tickmarks) const
 {
     WebVector<WebRect> webTickmarks;
-    m_scrollbar->getTickmarks(webTickmarks);
+    m_scrollbar.getTickmarks(webTickmarks);
     tickmarks.resize(webTickmarks.size());
     for (size_t i = 0; i < webTickmarks.size(); ++i)
         tickmarks[i] = webTickmarks[i];
@@ -125,7 +125,7 @@ void WebScrollbarThemeClientImpl::getTickmarks(Vector<IntRect>& tickmarks) const
 
 bool WebScrollbarThemeClientImpl::isScrollableAreaActive() const
 {
-    return m_scrollbar->isScrollableAreaActive();
+    return m_scrollbar.isScrollableAreaActive();
 }
 
 IntPoint WebScrollbarThemeClientImpl::convertFromRootFrame(const IntPoint& pointInRootFrame) const
@@ -137,22 +137,22 @@ IntPoint WebScrollbarThemeClientImpl::convertFromRootFrame(const IntPoint& point
 
 bool WebScrollbarThemeClientImpl::isCustomScrollbar() const
 {
-    return m_scrollbar->isCustomScrollbar();
+    return m_scrollbar.isCustomScrollbar();
 }
 
 ScrollbarOrientation WebScrollbarThemeClientImpl::orientation() const
 {
-    return static_cast<ScrollbarOrientation>(m_scrollbar->orientation());
+    return static_cast<ScrollbarOrientation>(m_scrollbar.orientation());
 }
 
 bool WebScrollbarThemeClientImpl::isLeftSideVerticalScrollbar() const
 {
-    return m_scrollbar->isLeftSideVerticalScrollbar();
+    return m_scrollbar.isLeftSideVerticalScrollbar();
 }
 
 int WebScrollbarThemeClientImpl::value() const
 {
-    return m_scrollbar->value();
+    return m_scrollbar.value();
 }
 
 float WebScrollbarThemeClientImpl::currentPos() const
@@ -167,27 +167,27 @@ int WebScrollbarThemeClientImpl::visibleSize() const
 
 int WebScrollbarThemeClientImpl::totalSize() const
 {
-    return m_scrollbar->totalSize();
+    return m_scrollbar.totalSize();
 }
 
 int WebScrollbarThemeClientImpl::maximum() const
 {
-    return m_scrollbar->maximum();
+    return m_scrollbar.maximum();
 }
 
 ScrollbarControlSize WebScrollbarThemeClientImpl::controlSize() const
 {
-    return static_cast<ScrollbarControlSize>(m_scrollbar->controlSize());
+    return static_cast<ScrollbarControlSize>(m_scrollbar.controlSize());
 }
 
 ScrollbarPart WebScrollbarThemeClientImpl::pressedPart() const
 {
-    return static_cast<ScrollbarPart>(m_scrollbar->pressedPart());
+    return static_cast<ScrollbarPart>(m_scrollbar.pressedPart());
 }
 
 ScrollbarPart WebScrollbarThemeClientImpl::hoveredPart() const
 {
-    return static_cast<ScrollbarPart>(m_scrollbar->hoveredPart());
+    return static_cast<ScrollbarPart>(m_scrollbar.hoveredPart());
 }
 
 void WebScrollbarThemeClientImpl::styleChanged()
@@ -201,7 +201,7 @@ void WebScrollbarThemeClientImpl::visibilityChanged()
 
 bool WebScrollbarThemeClientImpl::enabled() const
 {
-    return m_scrollbar->enabled();
+    return m_scrollbar.enabled();
 }
 
 void WebScrollbarThemeClientImpl::setEnabled(bool)
@@ -211,27 +211,27 @@ void WebScrollbarThemeClientImpl::setEnabled(bool)
 
 bool WebScrollbarThemeClientImpl::isOverlayScrollbar() const
 {
-    return m_scrollbar->isOverlay();
+    return m_scrollbar.isOverlay();
 }
 
 bool WebScrollbarThemeClientImpl::isAlphaLocked() const
 {
-    return m_scrollbar->isAlphaLocked();
+    return m_scrollbar.isAlphaLocked();
 }
 
 void WebScrollbarThemeClientImpl::setIsAlphaLocked(bool flag)
 {
-    m_scrollbar->setIsAlphaLocked(flag);
+    m_scrollbar.setIsAlphaLocked(flag);
 }
 
 float WebScrollbarThemeClientImpl::elasticOverscroll() const
 {
-    return m_scrollbar->elasticOverscroll();
+    return m_scrollbar.elasticOverscroll();
 }
 
 void WebScrollbarThemeClientImpl::setElasticOverscroll(float elasticOverscroll)
 {
-    return m_scrollbar->setElasticOverscroll(elasticOverscroll);
+    return m_scrollbar.setElasticOverscroll(elasticOverscroll);
 }
 
 bool WebScrollbarThemeClientImpl::trackNeedsRepaint() const