Rename VisualViewport::MainFrame() to LocalMainFrame() for readability.

The function VisualViewport::MainFrame() is often used in if-statements
to test for the existence of a *local* mainframe. But since we could
also have a remote mainframe, or no mainframe at all, the name is
ambiguous. This CL renames the function to make it clear what condition
is actually being tested.

This CL is a cleanup-refactor prior to landing a fix for the associated
issue.

Bug: 1150977
Change-Id: Id1542e46516288b15306be6ba75ff1805206ddc7
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2585634Reviewed-by: David Bokan <bokan@chromium.org>
Commit-Queue: James MacLean <wjmaclean@chromium.org>
Cr-Commit-Position: refs/heads/master@{#836170}

third_party/blink/renderer/core/frame/visual_viewport.cc

@@ -219,8 +219,8 @@ PaintPropertyChangeType VisualViewport::UpdatePaintPropertyNodesIfNeeded(
     state.max_scroll_offset_affected_by_page_scale = true;
     state.compositor_element_id = GetScrollElementId();
 
-    if (MainFrame() && MainFrame()->GetDocument()) {
-      Document* document = MainFrame()->GetDocument();
+    if (LocalMainFrame() && LocalMainFrame()->GetDocument()) {
+      Document* document = LocalMainFrame()->GetDocument();
       bool uses_default_root_scroller =
           &document->GetRootScrollerController().EffectiveRootScroller() ==
           document;
@@ -238,8 +238,8 @@ PaintPropertyChangeType VisualViewport::UpdatePaintPropertyNodesIfNeeded(
       state.prevent_viewport_scrolling_from_inner = !uses_default_root_scroller;
     }
 
-    if (MainFrame() &&
-        !MainFrame()->GetSettings()->GetThreadedScrollingEnabled()) {
+    if (LocalMainFrame() &&
+        !LocalMainFrame()->GetSettings()->GetThreadedScrollingEnabled()) {
       state.main_thread_scrolling_reasons =
           cc::MainThreadScrollingReason::kThreadedScrollingDisabled;
     }
@@ -325,8 +325,10 @@ PaintPropertyChangeType VisualViewport::UpdatePaintPropertyNodesIfNeeded(
   parent_property_tree_state_ =
       PropertyTreeStateOrAlias(*transform_parent, *clip_parent, *effect_parent);
 
-  if (change == PaintPropertyChangeType::kNodeAddedOrRemoved && MainFrame())
-    MainFrame()->View()->SetVisualViewportNeedsRepaint();
+  if (change == PaintPropertyChangeType::kNodeAddedOrRemoved &&
+      LocalMainFrame()) {
+    LocalMainFrame()->View()->SetVisualViewportNeedsRepaint();
+  }
 
   return change;
 }
@@ -341,20 +343,20 @@ void VisualViewport::Trace(Visitor* visitor) const {
 }
 
 void VisualViewport::UpdateStyleAndLayout(DocumentUpdateReason reason) const {
-  if (!MainFrame())
+  if (!LocalMainFrame())
     return;
 
-  if (Document* document = MainFrame()->GetDocument())
+  if (Document* document = LocalMainFrame()->GetDocument())
     document->UpdateStyleAndLayout(reason);
 }
 
 void VisualViewport::EnqueueScrollEvent() {
-  if (Document* document = MainFrame()->GetDocument())
+  if (Document* document = LocalMainFrame()->GetDocument())
     document->EnqueueVisualViewportScrollEvent();
 }
 
 void VisualViewport::EnqueueResizeEvent() {
-  if (Document* document = MainFrame()->GetDocument())
+  if (Document* document = LocalMainFrame()->GetDocument())
     document->EnqueueVisualViewportResizeEvent();
 }
 
@@ -370,7 +372,7 @@ void VisualViewport::SetSize(const IntSize& size) {
   TRACE_EVENT_INSTANT1("loading", "viewport", TRACE_EVENT_SCOPE_THREAD, "data",
                        ViewportToTracedValue());
 
-  if (!MainFrame())
+  if (!LocalMainFrame())
     return;
 
   // Need to re-compute sizes for the overlay scrollbars.
@@ -378,7 +380,7 @@ void VisualViewport::SetSize(const IntSize& size) {
     DCHECK(scrollbar_layer_vertical_);
     UpdateScrollbarLayer(kHorizontalScrollbar);
     UpdateScrollbarLayer(kVerticalScrollbar);
-    MainFrame()->View()->SetVisualViewportNeedsRepaint();
+    LocalMainFrame()->View()->SetVisualViewportNeedsRepaint();
   }
 
   EnqueueResizeEvent();
@@ -433,21 +435,21 @@ void VisualViewport::SetScale(float scale) {
 }
 
 double VisualViewport::OffsetLeft() const {
-  if (!MainFrame())
+  if (!LocalMainFrame())
     return 0;
 
   UpdateStyleAndLayout(DocumentUpdateReason::kJavaScript);
 
-  return VisibleRect().X() / MainFrame()->PageZoomFactor();
+  return VisibleRect().X() / LocalMainFrame()->PageZoomFactor();
 }
 
 double VisualViewport::OffsetTop() const {
-  if (!MainFrame())
+  if (!LocalMainFrame())
     return 0;
 
   UpdateStyleAndLayout(DocumentUpdateReason::kJavaScript);
 
-  return VisibleRect().Y() / MainFrame()->PageZoomFactor();
+  return VisibleRect().Y() / LocalMainFrame()->PageZoomFactor();
 }
 
 double VisualViewport::Width() const {
@@ -469,7 +471,7 @@ void VisualViewport::SetScaleAndLocation(float scale,
                                          const FloatPoint& location) {
   if (DidSetScaleOrLocation(scale, is_pinch_gesture_active, location)) {
     NotifyRootFrameViewport();
-    Document* document = MainFrame()->GetDocument();
+    Document* document = LocalMainFrame()->GetDocument();
     if (AXObjectCache* cache = document->ExistingAXObjectCache()) {
       cache->HandleScaleAndLocationChanged(document);
     }
@@ -477,19 +479,19 @@ void VisualViewport::SetScaleAndLocation(float scale,
 }
 
 double VisualViewport::VisibleWidthCSSPx() const {
-  if (!MainFrame())
+  if (!LocalMainFrame())
     return 0;
 
-  float zoom = MainFrame()->PageZoomFactor();
+  float zoom = LocalMainFrame()->PageZoomFactor();
   float width_css_px = VisibleRect().Width() / zoom;
   return width_css_px;
 }
 
 double VisualViewport::VisibleHeightCSSPx() const {
-  if (!MainFrame())
+  if (!LocalMainFrame())
     return 0;
 
-  float zoom = MainFrame()->PageZoomFactor();
+  float zoom = LocalMainFrame()->PageZoomFactor();
   float height_css_px = VisibleRect().Height() / zoom;
   return height_css_px;
 }
@@ -497,7 +499,7 @@ double VisualViewport::VisibleHeightCSSPx() const {
 bool VisualViewport::DidSetScaleOrLocation(float scale,
                                            bool is_pinch_gesture_active,
                                            const FloatPoint& location) {
-  if (!MainFrame())
+  if (!LocalMainFrame())
     return false;
 
   bool values_changed = false;
@@ -539,20 +541,20 @@ bool VisualViewport::DidSetScaleOrLocation(float scale,
     // ScrollingCoordinator.
     if (auto* coordinator = GetPage().GetScrollingCoordinator()) {
       if (scroll_layer_)
-        coordinator->UpdateCompositorScrollOffset(*MainFrame(), *this);
+        coordinator->UpdateCompositorScrollOffset(*LocalMainFrame(), *this);
     }
 
     EnqueueScrollEvent();
 
-    MainFrame()->View()->DidChangeScrollOffset();
+    LocalMainFrame()->View()->DidChangeScrollOffset();
     values_changed = true;
   }
 
   if (!values_changed)
     return false;
 
-  probe::DidChangeViewport(MainFrame());
-  MainFrame()->Loader().SaveScrollState();
+  probe::DidChangeViewport(LocalMainFrame());
+  LocalMainFrame()->Loader().SaveScrollState();
 
   ClampToBoundaries();
 
@@ -588,8 +590,8 @@ void VisualViewport::CreateLayers() {
 
   InitializeScrollbars();
 
-  if (MainFrame())
-    coordinator->UpdateCompositorScrollOffset(*MainFrame(), *this);
+  if (LocalMainFrame())
+    coordinator->UpdateCompositorScrollOffset(*LocalMainFrame(), *this);
 }
 
 void VisualViewport::InitializeScrollbars() {
@@ -610,7 +612,7 @@ void VisualViewport::InitializeScrollbars() {
   // Ensure existing LocalFrameView scrollbars are removed if the visual
   // viewport scrollbars are now supplied, or created if the visual viewport no
   // longer supplies scrollbars.
-  LocalFrame* frame = MainFrame();
+  LocalFrame* frame = LocalMainFrame();
   if (frame && frame->View())
     frame->View()->VisualViewportScrollbarsChanged();
 }
@@ -654,7 +656,7 @@ bool VisualViewport::VisualViewportSuppliesScrollbars() const {
 }
 
 const Document* VisualViewport::GetDocument() const {
-  return MainFrame() ? MainFrame()->GetDocument() : nullptr;
+  return LocalMainFrame() ? LocalMainFrame()->GetDocument() : nullptr;
 }
 
 CompositorElementId VisualViewport::GetScrollElementId() const {
@@ -670,9 +672,9 @@ ChromeClient* VisualViewport::GetChromeClient() const {
 }
 
 SmoothScrollSequencer* VisualViewport::GetSmoothScrollSequencer() const {
-  if (!MainFrame())
+  if (!LocalMainFrame())
     return nullptr;
-  return &MainFrame()->GetSmoothScrollSequencer();
+  return &LocalMainFrame()->GetSmoothScrollSequencer();
 }
 
 void VisualViewport::SetScrollOffset(
@@ -742,7 +744,7 @@ IntSize VisualViewport::MaximumScrollOffsetInt() const {
 }
 
 ScrollOffset VisualViewport::MaximumScrollOffset() const {
-  if (!MainFrame())
+  if (!LocalMainFrame())
     return ScrollOffset();
 
   // TODO(bokan): We probably shouldn't be storing the bounds in a float.
@@ -768,10 +770,10 @@ ScrollOffset VisualViewport::MaximumScrollOffset() const {
 
 IntPoint VisualViewport::ClampDocumentOffsetAtScale(const IntPoint& offset,
                                                     float scale) {
-  if (!MainFrame() || !MainFrame()->View())
+  if (!LocalMainFrame() || !LocalMainFrame()->View())
     return IntPoint();
 
-  LocalFrameView* view = MainFrame()->View();
+  LocalFrameView* view = LocalMainFrame()->View();
 
   FloatSize scaled_size(ExcludeScrollbars(size_));
   scaled_size.Scale(1 / scale);
@@ -805,7 +807,8 @@ float VisualViewport::BrowserControlsAdjustment() const {
 bool VisualViewport::UserInputScrollable(ScrollbarOrientation) const {
   // If there is a non-root fullscreen element, prevent the viewport from
   // scrolling.
-  Document* main_document = MainFrame() ? MainFrame()->GetDocument() : nullptr;
+  Document* main_document =
+      LocalMainFrame() ? LocalMainFrame()->GetDocument() : nullptr;
   if (main_document) {
     Element* fullscreen_element =
         Fullscreen::FullscreenElementFrom(*main_document);
@@ -816,7 +819,7 @@ bool VisualViewport::UserInputScrollable(ScrollbarOrientation) const {
 }
 
 IntSize VisualViewport::ContentsSize() const {
-  LocalFrame* frame = MainFrame();
+  LocalFrame* frame = LocalMainFrame();
   if (!frame || !frame->View())
     return IntSize();
 
@@ -830,11 +833,11 @@ IntRect VisualViewport::VisibleContentRect(
 
 scoped_refptr<base::SingleThreadTaskRunner> VisualViewport::GetTimerTaskRunner()
     const {
-  return MainFrame()->GetTaskRunner(TaskType::kInternalDefault);
+  return LocalMainFrame()->GetTaskRunner(TaskType::kInternalDefault);
 }
 
 mojom::blink::ColorScheme VisualViewport::UsedColorScheme() const {
-  if (LocalFrame* main_frame = MainFrame()) {
+  if (LocalFrame* main_frame = LocalMainFrame()) {
     if (Document* main_document = main_frame->GetDocument())
       return main_document->GetLayoutView()->StyleRef().UsedColorScheme();
   }
@@ -867,13 +870,13 @@ cc::Layer* VisualViewport::LayerForVerticalScrollbar() const {
 }
 
 RootFrameViewport* VisualViewport::GetRootFrameViewport() const {
-  if (!MainFrame() || !MainFrame()->View())
+  if (!LocalMainFrame() || !LocalMainFrame()->View())
     return nullptr;
 
-  return MainFrame()->View()->GetRootFrameViewport();
+  return LocalMainFrame()->View()->GetRootFrameViewport();
 }
 
-LocalFrame* VisualViewport::MainFrame() const {
+LocalFrame* VisualViewport::LocalMainFrame() const {
   return GetPage().MainFrame() && GetPage().MainFrame()->IsLocalFrame()
              ? GetPage().DeprecatedLocalMainFrame()
              : nullptr;
@@ -889,7 +892,7 @@ IntSize VisualViewport::ExcludeScrollbars(const IntSize& size) const {
 }
 
 bool VisualViewport::ScheduleAnimation() {
-  GetPage().GetChromeClient().ScheduleAnimation(MainFrame()->View());
+  GetPage().GetChromeClient().ScheduleAnimation(LocalMainFrame()->View());
   return true;
 }
 
@@ -956,10 +959,10 @@ IntPoint VisualViewport::RootFrameToViewport(
 }
 
 void VisualViewport::StartTrackingPinchStats() {
-  if (!MainFrame())
+  if (!LocalMainFrame())
     return;
 
-  Document* document = MainFrame()->GetDocument();
+  Document* document = LocalMainFrame()->GetDocument();
   if (!document)
     return;
 
@@ -998,10 +1001,10 @@ void VisualViewport::SendUMAMetrics() {
 }
 
 bool VisualViewport::ShouldDisableDesktopWorkarounds() const {
-  if (!MainFrame() || !MainFrame()->View())
+  if (!LocalMainFrame() || !LocalMainFrame()->View())
     return false;
 
-  if (!MainFrame()->GetSettings()->GetViewportEnabled())
+  if (!LocalMainFrame()->GetSettings()->GetViewportEnabled())
     return false;
 
   // A document is considered adapted to small screen UAs if one of these holds:
@@ -1011,7 +1014,7 @@ bool VisualViewport::ShouldDisableDesktopWorkarounds() const {
   const PageScaleConstraints& constraints =
       GetPage().GetPageScaleConstraintsSet().PageDefinedConstraints();
 
-  return MainFrame()->View()->GetLayoutSize().Width() == size_.Width() ||
+  return LocalMainFrame()->View()->GetLayoutSize().Width() == size_.Width() ||
          (constraints.minimum_scale == constraints.maximum_scale &&
           constraints.minimum_scale != -1);
 }
@@ -1041,8 +1044,8 @@ ScrollbarTheme& VisualViewport::GetPageScrollbarTheme() const {
 }
 
 PaintArtifactCompositor* VisualViewport::GetPaintArtifactCompositor() const {
-  if (MainFrame() && MainFrame()->View())
-    return MainFrame()->View()->GetPaintArtifactCompositor();
+  if (LocalMainFrame() && LocalMainFrame()->View())
+    return LocalMainFrame()->View()->GetPaintArtifactCompositor();
   return nullptr;
 }
 

third_party/blink/renderer/core/frame/visual_viewport.h

@@ -289,7 +289,7 @@ class CORE_EXPORT VisualViewport : public GarbageCollected<VisualViewport>,
 
   RootFrameViewport* GetRootFrameViewport() const;
 
-  LocalFrame* MainFrame() const;
+  LocalFrame* LocalMainFrame() const;
 
   Page& GetPage() const {
     DCHECK(page_);