Declare that LayoutEmbeddedContent always wraps an HTMLFrameOwnerElement

LayoutEmbeddedContent is constructed for HTMLPluginElement,
HTMLFrameElement, HTMLPortalElement and HTMLIFrameElement. All of these
are of type HTMLFrameOwnerElement so the dynamic casts and type checks
are unnecessary. Unfortunately, since the LayoutEmbeddedContent object
can outlive the HTMLFrameOwnerElement, null checks are still necessary.

Bug: None
Change-Id: I33d3fc5654d73f92f10d302429dc3713592455a8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1866016Reviewed-by: Morten Stenshorne <mstensho@chromium.org>
Reviewed-by: Yi Gu <yigu@chromium.org>
Commit-Queue: Robert Flack <flackr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#706988}

third_party/blink/renderer/core/layout/layout_embedded_content.cc

@@ -41,7 +41,7 @@
 
 namespace blink {
 
-LayoutEmbeddedContent::LayoutEmbeddedContent(Element* element)
+LayoutEmbeddedContent::LayoutEmbeddedContent(HTMLFrameOwnerElement* element)
     : LayoutReplaced(element),
       // Reference counting is used to prevent the part from being destroyed
       // while inside the EmbeddedContentView code, which might not be able to
@@ -62,7 +62,7 @@ void LayoutEmbeddedContent::WillBeDestroyed() {
     cache->Remove(this);
   }
 
-  if (auto* frame_owner = DynamicTo<HTMLFrameOwnerElement>(GetNode()))
+  if (auto* frame_owner = GetFrameOwnerElement())
     frame_owner->SetEmbeddedContentView(nullptr);
 
   LayoutReplaced::WillBeDestroyed();
@@ -77,7 +77,7 @@ void LayoutEmbeddedContent::Destroy() {
   // Release()).
   //
   // But, we've told the system we've destroyed the layoutObject, which happens
-  // when the DOM node is destroyed. So there is a good change the DOM node this
+  // when the DOM node is destroyed. So there is a good chance the DOM node this
   // object points too is invalid, so we have to clear the node so we make sure
   // we don't access it in the future.
   ClearNode();
@@ -100,8 +100,8 @@ WebPluginContainerImpl* LayoutEmbeddedContent::Plugin() const {
 }
 
 EmbeddedContentView* LayoutEmbeddedContent::GetEmbeddedContentView() const {
-  if (auto* frame_owner_element = DynamicTo<HTMLFrameOwnerElement>(GetNode()))
-    return frame_owner_element->OwnedEmbeddedContentView();
+  if (auto* frame_owner = GetFrameOwnerElement())
+    return frame_owner->OwnedEmbeddedContentView();
   return nullptr;
 }
 
@@ -124,7 +124,7 @@ bool LayoutEmbeddedContent::RequiresAcceleratedCompositing() const {
   if (plugin_view && plugin_view->CcLayer())
     return true;
 
-  auto* element = DynamicTo<HTMLFrameOwnerElement>(GetNode());
+  auto* element = GetFrameOwnerElement();
   if (!element)
     return false;
 
@@ -268,7 +268,7 @@ void LayoutEmbeddedContent::StyleDidChange(StyleDifference diff,
     return;
   }
 
-  auto* frame_owner = DynamicTo<HTMLFrameOwnerElement>(GetNode());
+  auto* frame_owner = GetFrameOwnerElement();
   if (!frame_owner)
     return;
 

third_party/blink/renderer/core/layout/layout_embedded_content.h

@@ -24,6 +24,7 @@
 #define THIRD_PARTY_BLINK_RENDERER_CORE_LAYOUT_LAYOUT_EMBEDDED_CONTENT_H_
 
 #include "third_party/blink/renderer/core/core_export.h"
+#include "third_party/blink/renderer/core/html/html_frame_owner_element.h"
 #include "third_party/blink/renderer/core/layout/layout_replaced.h"
 
 namespace blink {
@@ -36,7 +37,7 @@ class WebPluginContainerImpl;
 // LayoutEmbeddedObject.
 class CORE_EXPORT LayoutEmbeddedContent : public LayoutReplaced {
  public:
-  explicit LayoutEmbeddedContent(Element*);
+  explicit LayoutEmbeddedContent(HTMLFrameOwnerElement*);
   ~LayoutEmbeddedContent() override;
 
   bool RequiresAcceleratedCompositing() const;
@@ -90,6 +91,10 @@ class CORE_EXPORT LayoutEmbeddedContent : public LayoutReplaced {
       const PhysicalOffset& accumulated_offset,
       HitTestAction);
 
+  HTMLFrameOwnerElement* GetFrameOwnerElement() const {
+    return To<HTMLFrameOwnerElement>(GetNode());
+  }
+
   int ref_count_;
 };
 

third_party/blink/renderer/core/layout/layout_embedded_content_test.cc

@@ -14,7 +14,7 @@ class LayoutEmbeddedContentTest : public RenderingTest {};
 
 class OverriddenLayoutEmbeddedContent : public LayoutEmbeddedContent {
  public:
-  explicit OverriddenLayoutEmbeddedContent(Element* element)
+  explicit OverriddenLayoutEmbeddedContent(HTMLFrameOwnerElement* element)
       : LayoutEmbeddedContent(element) {}
 
   const char* GetName() const override {

third_party/blink/renderer/core/layout/layout_embedded_object.cc

@@ -39,7 +39,7 @@
 
 namespace blink {
 
-LayoutEmbeddedObject::LayoutEmbeddedObject(Element* element)
+LayoutEmbeddedObject::LayoutEmbeddedObject(HTMLFrameOwnerElement* element)
     : LayoutEmbeddedContent(element) {
   View()->GetFrameView()->SetIsVisuallyNonEmpty();
 }

third_party/blink/renderer/core/layout/layout_embedded_object.h

@@ -32,7 +32,7 @@ namespace blink {
 // plugins. For example, <embed src="foo.html"> does not invoke a plugin.
 class LayoutEmbeddedObject final : public LayoutEmbeddedContent {
  public:
-  LayoutEmbeddedObject(Element*);
+  LayoutEmbeddedObject(HTMLFrameOwnerElement*);
   ~LayoutEmbeddedObject() override;
 
   enum PluginAvailability {

third_party/blink/renderer/core/layout/layout_iframe.cc

@@ -30,7 +30,8 @@
 
 namespace blink {
 
-LayoutIFrame::LayoutIFrame(Element* element) : LayoutEmbeddedContent(element) {}
+LayoutIFrame::LayoutIFrame(HTMLFrameOwnerElement* element)
+    : LayoutEmbeddedContent(element) {}
 
 bool LayoutIFrame::ShouldComputeSizeAsReplaced() const {
   return true;

third_party/blink/renderer/core/layout/layout_iframe.h

@@ -32,7 +32,7 @@ namespace blink {
 
 class LayoutIFrame final : public LayoutEmbeddedContent {
  public:
-  explicit LayoutIFrame(Element*);
+  explicit LayoutIFrame(HTMLFrameOwnerElement*);
 
   const char* GetName() const override { return "LayoutIFrame"; }