Change VisualViewport to store a Page instead of a FrameHost

This is part of the work to remove FrameHost.

BUG=691794

Review-Url: https://codereview.chromium.org/2727563004
Cr-Commit-Position: refs/heads/master@{#455987}

third_party/WebKit/Source/core/frame/FrameHost.cpp

@@ -47,7 +47,7 @@ FrameHost* FrameHost::create(Page& page) {
 
 FrameHost::FrameHost(Page& page)
     : m_page(&page),
-      m_visualViewport(VisualViewport::create(*this)),
+      m_visualViewport(VisualViewport::create(page)),
       m_overscrollController(
           OverscrollController::create(*m_visualViewport,
                                        m_page->chromeClient())),

third_party/WebKit/Source/core/frame/VisualViewport.cpp

@@ -60,8 +60,8 @@
 
 namespace blink {
 
-VisualViewport::VisualViewport(FrameHost& owner)
-    : m_frameHost(&owner),
+VisualViewport::VisualViewport(Page& owner)
+    : m_page(&owner),
       m_scale(1),
       m_browserControlsAdjustment(0),
       m_maxPageScale(-1),
@@ -74,7 +74,7 @@ VisualViewport::~VisualViewport() {
 }
 
 DEFINE_TRACE(VisualViewport) {
-  visitor->trace(m_frameHost);
+  visitor->trace(m_page);
   ScrollableArea::trace(visitor);
 }
 

third_party/WebKit/Source/core/frame/VisualViewport.h

@@ -34,7 +34,6 @@
 #include <memory>
 #include "core/CoreExport.h"
 #include "core/events/Event.h"
-#include "core/frame/FrameHost.h"
 #include "platform/geometry/FloatRect.h"
 #include "platform/geometry/FloatSize.h"
 #include "platform/geometry/IntSize.h"
@@ -89,9 +88,7 @@ class CORE_EXPORT VisualViewport final
   USING_GARBAGE_COLLECTED_MIXIN(VisualViewport);
 
  public:
-  static VisualViewport* create(FrameHost& host) {
-    return new VisualViewport(host);
-  }
+  static VisualViewport* create(Page& host) { return new VisualViewport(host); }
   ~VisualViewport() override;
 
   DECLARE_VIRTUAL_TRACE();
@@ -236,7 +233,7 @@ class CORE_EXPORT VisualViewport final
   bool shouldDisableDesktopWorkarounds() const;
 
  private:
-  explicit VisualViewport(FrameHost&);
+  explicit VisualViewport(Page&);
 
   bool didSetScaleOrLocation(float scale, const FloatPoint& location);
 
@@ -266,11 +263,11 @@ class CORE_EXPORT VisualViewport final
   LocalFrame* mainFrame() const;
 
   Page& page() const {
-    DCHECK(m_frameHost);
-    return m_frameHost->page();
+    DCHECK(m_page);
+    return *m_page;
   }
 
-  Member<FrameHost> m_frameHost;
+  Member<Page> m_page;
   std::unique_ptr<GraphicsLayer> m_rootTransformLayer;
   std::unique_ptr<GraphicsLayer> m_innerViewportContainerLayer;
   std::unique_ptr<GraphicsLayer> m_overscrollElasticityLayer;