Revert of Add a scroll offset to PDF documents to account for the top material design toolbar. (patchset #7 id:120001 of https://codereview.chromium.org/1255403002/ )

Reason for revert:
This patch breaks print preview.

BUG=516829

Original issue's description:
> Add a scroll offset to PDF documents to account for the top material design toolbar.
>
> Previously the toolbar in the material design PDF UI would always cover the top
> of pages when it was first loaded or when a page was navigated to using the
> page selector. Now we ensure that a blank region is left at the very top of
> the document when it is first loaded. This is the region that the toolbar
> covers, so the document is not obscured at all. When pages are navigated to, we
> ensure that the top of the selected page is always underneath the toolbar
> so that it is not obscured. The one exception to this is when in fit-to-page
> mode which causes the page to be zoomed to cover the entire screen, ignoring
> the toolbar. This is so that users can take advantaging of filling all of the
> screen real-estate with a page when that is what they want.
>
> This is implemented by initially scrolling the document to a negative offset
> (which is equal to the toolbar height). All subsequent scrolls are relative
> to this initial scroll. A few small bugs that assumed there was no blank space
> above the first page have also been fixed.
>
> BUG=439114
>
> Committed: https://crrev.com/daad0f1f879b13c8b55797ae5ce106d382283047
> Cr-Commit-Position: refs/heads/master@{#341685}

TBR=sammc@chromium.org,tsergeant@chromium.org,raymes@chromium.org
BUG=439114

Review URL: https://codereview.chromium.org/1267553004

Cr-Commit-Position: refs/heads/master@{#341820}

2 files changed, 4 insertions, 10 deletions

diff --git a/pdf/pdfium/pdfium_engine.cc b/pdf/pdfium/pdfium_engine.cc
index fc36c1e..89fa7eb 100644
--- a/pdf/pdfium/pdfium_engine.cc
+++ b/pdf/pdfium/pdfium_engine.cc
@@ -1071,15 +1071,6 @@ void PDFiumEngine::Paint(const pp::Rect& rect,
     if (dirty_in_screen.IsEmpty())
       continue;
 
-    // Compute the leftover dirty region. The first page may have blank space
-    // above it, in which case we also need to subtract that space from the
-    // dirty region.
-    if (i == 0) {
-      pp::Rect blank_space_in_screen = dirty_in_screen;
-      blank_space_in_screen.set_y(0);
-      blank_space_in_screen.set_height(dirty_in_screen.y());
-      leftover = leftover.Subtract(blank_space_in_screen);
-    }
     leftover = leftover.Subtract(dirty_in_screen);
 
     if (pages_[index]->available()) {
diff --git a/pdf/pdfium/pdfium_engine.h b/pdf/pdfium/pdfium_engine.h
index c8ee6bd..ff45f45 100644
--- a/pdf/pdfium/pdfium_engine.h
+++ b/pdf/pdfium/pdfium_engine.h
@@ -84,7 +84,6 @@ class PDFiumEngine : public PDFEngine,
   virtual int GetMostVisiblePage();
   virtual pp::Rect GetPageRect(int index);
   virtual pp::Rect GetPageContentsRect(int index);
-  virtual pp::Rect GetPageScreenRect(int page_index) const;
   virtual int GetVerticalScrollbarYPosition() { return position_.y(); }
   virtual void PaintThumbnail(pp::ImageData* image_data, int index);
   virtual void SetGrayscale(bool grayscale);
@@ -374,6 +373,10 @@ class PDFiumEngine : public PDFEngine,
   // Returns the currently visible rectangle in document coordinates.
   pp::Rect GetVisibleRect() const;
 
+  // Returns a page's rect in screen coordinates, as well as its surrounding
+  // border areas and bottom separator.
+  pp::Rect GetPageScreenRect(int page_index) const;
+
   // Given a rectangle in document coordinates, returns the rectange into screen
   // coordinates (i.e. 0,0 is top left corner of plugin area).  If it's not
   // visible, an empty rectangle is returned.