Make CPDF_Page retainable.

Small step to reducing the differences between XFA and non-XFA. We
still use the RetainPtr pretty much as if it were an unique_ptr, in
that we're not yet caching pages and handing out multiple pointers
to the same page in the non-XFA case.

The one change is in page view cleanup, where we no longer need a
boolean and can take (sufficient) page ownership with a RetainPtr.

Tidy up some document.h -> page.h -> document.h circular inclusion
while we're at it.

NOTE: Wait for imminent branch to pass before landing. We'll want
this to bake a while.

Change-Id: I64a2f12ac3424ece1063d40583995b834117cf34
Reviewed-on: https://pdfium-review.googlesource.com/32790
Reviewed-by: dsinclair <dsinclair@chromium.org>
Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Tom Sepez <tsepez@chromium.org>

1 files changed, 9 insertions, 11 deletions

diff --git a/core/fpdfapi/page/cpdf_page.h b/core/fpdfapi/page/cpdf_page.h
index 28a12f45b5..0bb99b73f1 100644
--- a/core/fpdfapi/page/cpdf_page.h
+++ b/core/fpdfapi/page/cpdf_page.h
@@ -10,7 +10,6 @@
 #include <memory>
 
 #include "core/fpdfapi/page/cpdf_pageobjectholder.h"
-#include "core/fpdfapi/parser/cpdf_document.h"
 #include "core/fxcrt/fx_coordinates.h"
 #include "core/fxcrt/fx_system.h"
 #include "core/fxcrt/retain_ptr.h"
@@ -23,19 +22,13 @@ class CPDF_Object;
 class CPDF_PageRenderCache;
 class CPDF_PageRenderContext;
 
-class CPDF_Page : public CPDF_PageObjectHolder {
+class CPDF_Page : public Retainable, public CPDF_PageObjectHolder {
  public:
   class View {};  // Caller implements as desired, empty here due to layering.
+  class Extension : public Retainable {};  // XFA page parent class, layering.
 
-  // XFA page parent class, layering.
-  class Extension : public Retainable {
-    virtual CPDF_Document::Extension* GetDocumentExtension() const = 0;
-  };
-
-  CPDF_Page(CPDF_Document* pDocument,
-            CPDF_Dictionary* pPageDict,
-            bool bPageCache);
-  ~CPDF_Page() override;
+  template <typename T, typename... Args>
+  friend RetainPtr<T> pdfium::MakeRetain(Args&&... args);
 
   // CPDF_PageObjectHolder:
   bool IsPage() const override;
@@ -71,6 +64,11 @@ class CPDF_Page : public CPDF_PageObjectHolder {
   void SetPageExtension(Extension* pExt) { m_pPageExtension = pExt; }
 
  private:
+  CPDF_Page(CPDF_Document* pDocument,
+            CPDF_Dictionary* pPageDict,
+            bool bPageCache);
+  ~CPDF_Page() override;
+
   void StartParse();
 
   CPDF_Object* GetPageAttr(const ByteString& name) const;