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}

10 files changed, 44 insertions, 148 deletions

diff --git a/chrome/browser/resources/pdf/pdf.js b/chrome/browser/resources/pdf/pdf.js
index 3fb6148..dfa2d31 100644
--- a/chrome/browser/resources/pdf/pdf.js
+++ b/chrome/browser/resources/pdf/pdf.js
@@ -75,12 +75,6 @@ function shouldIgnoreKeyEvents(activeElement) {
 PDFViewer.MIN_TOOLBAR_OFFSET = 15;
 
 /**
- * The height of the toolbar along the top of the page. The document will be
- * shifted down by this much in the viewport.
- */
-PDFViewer.MATERIAL_TOOLBAR_HEIGHT = 64;
-
-/**
  * Creates a new PDFViewer. There should only be one of these objects per
  * document.
  * @constructor
@@ -110,16 +104,13 @@ function PDFViewer(browserApi) {
   this.errorScreen_ = $('error-screen');
 
   // Create the viewport.
-  var topToolbarHeight =
-      this.isMaterial_ ? PDFViewer.MATERIAL_TOOLBAR_HEIGHT : 0;
   this.viewport_ = new Viewport(window,
                                 this.sizer_,
                                 this.viewportChanged_.bind(this),
                                 this.beforeZoom_.bind(this),
                                 this.afterZoom_.bind(this),
                                 getScrollbarWidth(),
-                                this.browserApi_.getDefaultZoom(),
-                                topToolbarHeight);
+                                this.browserApi_.getDefaultZoom());
 
   // Create the plugin object dynamically so we can set its src. The plugin
   // element is sized to fill the entire window and is set to be fixed
@@ -152,11 +143,8 @@ function PDFViewer(browserApi) {
   }
   this.plugin_.setAttribute('headers', headers);
 
-  if (this.isMaterial_) {
+  if (this.isMaterial_)
     this.plugin_.setAttribute('is-material', '');
-    this.plugin_.setAttribute('top-toolbar-height',
-                              PDFViewer.MATERIAL_TOOLBAR_HEIGHT);
-  }
 
   if (!this.browserApi_.getStreamInfo().embedded)
     this.plugin_.setAttribute('full-frame', '');
diff --git a/chrome/browser/resources/pdf/viewport.js b/chrome/browser/resources/pdf/viewport.js
index 35a5f65..47c2507 100644
--- a/chrome/browser/resources/pdf/viewport.js
+++ b/chrome/browser/resources/pdf/viewport.js
@@ -25,8 +25,6 @@ function getIntersectionHeight(rect1, rect2) {
  * @param {Function} afterZoomCallback is run after a change in zoom
  * @param {number} scrollbarWidth the width of scrollbars on the page
  * @param {number} defaultZoom The default zoom level.
- * @param {number} topToolbarHeight The number of pixels that should initially
- *     be left blank above the document for the toolbar.
  */
 function Viewport(window,
                   sizer,
@@ -34,8 +32,7 @@ function Viewport(window,
                   beforeZoomCallback,
                   afterZoomCallback,
                   scrollbarWidth,
-                  defaultZoom,
-                  topToolbarHeight) {
+                  defaultZoom) {
   this.window_ = window;
   this.sizer_ = sizer;
   this.viewportChangedCallback_ = viewportChangedCallback;
@@ -48,7 +45,6 @@ function Viewport(window,
   this.scrollbarWidth_ = scrollbarWidth;
   this.fittingType_ = Viewport.FittingType.NONE;
   this.defaultZoom_ = defaultZoom;
-  this.topToolbarHeight_ = topToolbarHeight;
 
   window.addEventListener('scroll', this.updateViewport_.bind(this));
   window.addEventListener('resize', this.resize_.bind(this));
@@ -143,8 +139,8 @@ Viewport.prototype = {
     if (this.documentDimensions_) {
       this.sizer_.style.width =
           this.documentDimensions_.width * this.zoom_ + 'px';
-      this.sizer_.style.height = this.documentDimensions_.height * this.zoom_ +
-          this.topToolbarHeight_ + 'px';
+      this.sizer_.style.height =
+          this.documentDimensions_.height * this.zoom_ + 'px';
     }
   },
 
@@ -175,7 +171,7 @@ Viewport.prototype = {
   get position() {
     return {
       x: this.window_.pageXOffset,
-      y: this.window_.pageYOffset - this.topToolbarHeight_
+      y: this.window_.pageYOffset
     };
   },
 
@@ -184,7 +180,7 @@ Viewport.prototype = {
    * @type {Object} position the position to scroll to.
    */
   set position(position) {
-    this.window_.scrollTo(position.x, position.y + this.topToolbarHeight_);
+    this.window_.scrollTo(position.x, position.y);
   },
 
   /**
@@ -233,17 +229,15 @@ Viewport.prototype = {
             'Viewport.mightZoom_.';
     }
     // Record the scroll position (relative to the top-left of the window).
-    var currentScrollPos = {
-      x: this.position.x / this.zoom_,
-      y: this.position.y / this.zoom_
-    };
+    var currentScrollPos = [
+      this.window_.pageXOffset / this.zoom_,
+      this.window_.pageYOffset / this.zoom_
+    ];
     this.zoom_ = newZoom;
     this.contentSizeChanged_();
     // Scroll to the scaled scroll position.
-    this.position = {
-      x: currentScrollPos.x * newZoom,
-      y: currentScrollPos.y * newZoom
-    };
+    this.window_.scrollTo(currentScrollPos[0] * newZoom,
+                          currentScrollPos[1] * newZoom);
   },
 
   /**
@@ -432,12 +426,8 @@ Viewport.prototype = {
         height: this.pageDimensions_[page].height,
       };
       this.setZoomInternal_(this.computeFittingZoom_(dimensions, false));
-      if (scrollToTopOfPage) {
-        this.position = {
-          x: 0,
-          y: this.pageDimensions_[page].y * this.zoom_
-        };
-      }
+      if (scrollToTopOfPage)
+        this.window_.scrollTo(0, this.pageDimensions_[page].y * this.zoom_);
       this.updateViewport_();
     }.bind(this));
   },
@@ -495,16 +485,8 @@ Viewport.prototype = {
       if (page >= this.pageDimensions_.length)
         page = this.pageDimensions_.length - 1;
       var dimensions = this.pageDimensions_[page];
-      var toolbarOffset = 0;
-      // Unless we're in fit to page mode, scroll above the page by
-      // |this.topToolbarHeight_| so that the toolbar isn't covering it
-      // initially.
-      if (this.fittingType_ != Viewport.FittingType.FIT_TO_PAGE)
-        toolbarOffset = this.topToolbarHeight_;
-      this.position = {
-        x: dimensions.x * this.zoom_,
-        y: dimensions.y * this.zoom_ - toolbarOffset
-      };
+      this.window_.scrollTo(dimensions.x * this.zoom_,
+                            dimensions.y * this.zoom_);
       this.updateViewport_();
     }.bind(this));
   },
@@ -522,10 +504,7 @@ Viewport.prototype = {
         this.setZoomInternal_(
             Math.min(this.defaultZoom_,
                      this.computeFittingZoom_(this.documentDimensions_, true)));
-        this.position = {
-          x: 0,
-          y: -this.topToolbarHeight_
-        };
+        this.window_.scrollTo(0, 0);
       }
       this.contentSizeChanged_();
       this.resize_();
diff --git a/chrome/test/data/pdf/basic_plugin_test.js b/chrome/test/data/pdf/basic_plugin_test.js
index fc73d54..08d2714 100644
--- a/chrome/test/data/pdf/basic_plugin_test.js
+++ b/chrome/test/data/pdf/basic_plugin_test.js
@@ -18,8 +18,7 @@ var tests = [
     viewer.viewport.setZoom(1);
     var sizer = document.getElementById('sizer');
     chrome.test.assertEq(826, sizer.offsetWidth);
-    chrome.test.assertEq(1066 + viewer.viewport.topToolbarHeight_,
-                         sizer.offsetHeight);
+    chrome.test.assertEq(1066, sizer.offsetHeight);
     chrome.test.succeed();
   },
 
diff --git a/chrome/test/data/pdf/navigator_test.js b/chrome/test/data/pdf/navigator_test.js
index a7ffbbb..149fe2f 100644
--- a/chrome/test/data/pdf/navigator_test.js
+++ b/chrome/test/data/pdf/navigator_test.js
@@ -32,7 +32,7 @@ var tests = [
     var mockSizer = new MockSizer();
     var mockCallback = new MockViewportChangedCallback();
     var viewport = new Viewport(mockWindow, mockSizer, mockCallback.callback,
-                                function() {}, function() {}, 0, 1, 0);
+                                function() {}, function() {}, 0, 1);
 
     var paramsParser = new OpenPDFParamsParser(function(name) {
       if (name == 'US')
diff --git a/chrome/test/data/pdf/viewport_test.js b/chrome/test/data/pdf/viewport_test.js
index 1a45c63..a513de9 100644
--- a/chrome/test/data/pdf/viewport_test.js
+++ b/chrome/test/data/pdf/viewport_test.js
@@ -6,7 +6,7 @@ var tests = [
   function testDocumentNeedsScrollbars() {
     var viewport =
         new Viewport(new MockWindow(100, 100), new MockSizer(), function() {},
-                     function() {}, function() {}, 10, 1, 0);
+                     function() {}, function() {}, 10, 1);
     var scrollbars;
 
     viewport.setDocumentDimensions(new MockDocumentDimensions(90, 90));
@@ -61,7 +61,7 @@ var tests = [
     var mockWindow = new MockWindow(100, 100, mockSizer);
     var mockCallback = new MockViewportChangedCallback();
     var viewport = new Viewport(mockWindow, mockSizer, mockCallback.callback,
-                                function() {}, function() {}, 0, 1, 0);
+                                function() {}, function() {}, 0, 1);
 
     // Test setting the zoom without the document dimensions set. The sizer
     // shouldn't change size.
@@ -136,7 +136,7 @@ var tests = [
   function testGetMostVisiblePage() {
     var mockWindow = new MockWindow(100, 100);
     var viewport = new Viewport(mockWindow, new MockSizer(), function() {},
-                                function() {}, function() {}, 0, 1, 0);
+                                function() {}, function() {}, 0, 1);
 
     var documentDimensions = new MockDocumentDimensions(100, 100);
     documentDimensions.addPage(50, 100);
@@ -186,7 +186,7 @@ var tests = [
     var mockSizer = new MockSizer();
     var mockCallback = new MockViewportChangedCallback();
     var viewport = new Viewport(mockWindow, mockSizer, mockCallback.callback,
-                                function() {}, function() {}, 0, 1, 0);
+                                function() {}, function() {}, 0, 1);
     var documentDimensions = new MockDocumentDimensions();
 
     // Test with a document width which matches the window width.
@@ -245,7 +245,7 @@ var tests = [
     // fit to width, which will cause the page height to span outside of the
     // viewport, triggering 15px scrollbars to be shown.
     viewport = new Viewport(mockWindow, mockSizer, mockCallback.callback,
-                            function() {}, function() {}, 15, 1, 0);
+                            function() {}, function() {}, 15, 1);
     documentDimensions.reset();
     documentDimensions.addPage(50, 100);
     viewport.setDocumentDimensions(documentDimensions);
@@ -264,7 +264,7 @@ var tests = [
     var mockSizer = new MockSizer();
     var mockCallback = new MockViewportChangedCallback();
     var viewport = new Viewport(mockWindow, mockSizer, mockCallback.callback,
-                                function() {}, function() {}, 0, 1, 0);
+                                function() {}, function() {}, 0, 1);
     var documentDimensions = new MockDocumentDimensions();
 
     // Test with a page size which matches the window size.
@@ -373,7 +373,7 @@ var tests = [
     var mockSizer = new MockSizer();
     var mockCallback = new MockViewportChangedCallback();
     var viewport = new Viewport(mockWindow, mockSizer, mockCallback.callback,
-                                function() {}, function() {}, 0, 1, 0);
+                                function() {}, function() {}, 0, 1);
     var documentDimensions = new MockDocumentDimensions();
 
     documentDimensions.addPage(100, 100);
@@ -414,7 +414,7 @@ var tests = [
     var mockSizer = new MockSizer();
     var mockCallback = new MockViewportChangedCallback();
     var viewport = new Viewport(mockWindow, mockSizer, mockCallback.callback,
-                                function() {}, function() {}, 0, 1, 0);
+                                function() {}, function() {}, 0, 1);
     var documentDimensions = new MockDocumentDimensions();
     documentDimensions.addPage(100, 100);
     documentDimensions.addPage(200, 200);
@@ -469,7 +469,7 @@ var tests = [
         chrome.test.assertEq(1, viewport.zoom);
     };
     viewport = new Viewport(mockWindow, mockSizer, function() {},
-                            beforeZoom, afterZoom, 0, 1, 0);
+                            beforeZoom, afterZoom, 0, 1);
     viewport.setZoom(0.5);
     chrome.test.succeed();
   },
@@ -477,7 +477,7 @@ var tests = [
   function testInitialSetDocumentDimensionsZoomConstrained() {
     var viewport =
         new Viewport(new MockWindow(100, 100), new MockSizer(), function() {},
-                     function() {}, function() {}, 0, 1.2, 0);
+                     function() {}, function() {}, 0, 1.2);
     viewport.setDocumentDimensions(new MockDocumentDimensions(50, 50));
     chrome.test.assertEq(1.2, viewport.zoom);
     chrome.test.succeed();
@@ -486,52 +486,11 @@ var tests = [
   function testInitialSetDocumentDimensionsZoomUnconstrained() {
     var viewport = new Viewport(
         new MockWindow(100, 100),
-        new MockSizer(), function() {}, function() {}, function() {}, 0, 3, 0);
+        new MockSizer(), function() {}, function() {}, function() {}, 0, 3);
     viewport.setDocumentDimensions(new MockDocumentDimensions(50, 50));
     chrome.test.assertEq(2, viewport.zoom);
     chrome.test.succeed();
   },
-
-  function testToolbarHeightOffset() {
-    var mockSizer = new MockSizer();
-    var mockWindow = new MockWindow(100, 100);
-    var viewport = new Viewport(mockWindow,
-        mockSizer, function() {}, function() {}, function() {}, 0, 1, 50);
-    var documentDimensions = new MockDocumentDimensions(0, 0);
-    documentDimensions.addPage(50, 500);
-    viewport.setDocumentDimensions(documentDimensions);
-    viewport.setZoom(1);
-
-    // Check that the sizer incorporates the toolbar height.
-    chrome.test.assertEq('550px', mockSizer.style.height);
-    chrome.test.assertEq('50px', mockSizer.style.width);
-    chrome.test.assertEq(0, viewport.position.x);
-
-    // Check the sizer incorporates the toolbar height correctly even if zoomed.
-    viewport.setZoom(2);
-    chrome.test.assertEq('1050px', mockSizer.style.height);
-    chrome.test.assertEq('100px', mockSizer.style.width);
-
-    // Test that the viewport scrolls to the correct offset when fit-to-page is
-    // enabled. The top of the viewport should be at the start of the document.
-    viewport.fitToPage();
-    chrome.test.assertEq(0, viewport.position.y);
-
-    // Check that going to a page scrolls to the correct offset when fit-to-page
-    // is enabled. The top of the viewport should be at the start of the
-    // document.
-    mockWindow.scrollTo(0, 100);
-    viewport.goToPage(0);
-    chrome.test.assertEq(0, viewport.position.y);
-
-    // Check that going to a page scrolls to the correct offset when fit-to-page
-    // is not enabled. The top of the viewport should be before start of the
-    // document.
-    viewport.setZoom(1);
-    viewport.goToPage(0);
-    chrome.test.assertEq(-50, viewport.position.y);
-    chrome.test.succeed();
-  }
 ];
 
 chrome.test.runTests(tests);
diff --git a/pdf/out_of_process_instance.cc b/pdf/out_of_process_instance.cc
index 0637845..df18f17 100644
--- a/pdf/out_of_process_instance.cc
+++ b/pdf/out_of_process_instance.cc
@@ -278,8 +278,7 @@ OutOfProcessInstance::OutOfProcessInstance(PP_Instance instance)
       received_viewport_message_(false),
       did_call_start_loading_(false),
       stop_scrolling_(false),
-      background_color_(kBackgroundColor),
-      top_toolbar_height_(0) {
+      background_color_(kBackgroundColor) {
   loader_factory_.Initialize(this);
   timer_factory_.Initialize(this);
   form_factory_.Initialize(this);
@@ -356,8 +355,6 @@ bool OutOfProcessInstance::Init(uint32_t argc,
       headers = argv[i];
     else if (strcmp(argn[i], "is-material") == 0)
       is_material = true;
-    else if (strcmp(argn[i], "top-toolbar-height") == 0)
-      base::StringToInt(argv[i], &top_toolbar_height_);
   }
 
   if (is_material)
@@ -595,12 +592,8 @@ void OutOfProcessInstance::DidChangeView(const pp::View& view) {
 
   if (!stop_scrolling_) {
     pp::Point scroll_offset(view.GetScrollOffset());
-    // Because view messages come from the DOM, the coordinates of the viewport
-    // are 0-based (i.e. they do not correspond to the viewport's coordinates in
-    // JS), so we need to subtract the toolbar height to convert them into
-    // viewport coordinates.
     pp::FloatPoint scroll_offset_float(scroll_offset.x(),
-                                       scroll_offset.y() - top_toolbar_height_);
+                                       scroll_offset.y());
     scroll_offset_float = BoundScrollOffsetToDocument(scroll_offset_float);
     engine_->ScrolledToXPosition(scroll_offset_float.x() * device_scale_);
     engine_->ScrolledToYPosition(scroll_offset_float.y() * device_scale_);
@@ -733,15 +726,6 @@ void OutOfProcessInstance::OnPaint(
       }
     }
 
-    // Ensure the region above the first page (if any) is filled;
-    int32_t first_page_ypos = engine_->GetPageScreenRect(0).y();
-    if (rect.y() < first_page_ypos) {
-      pp::Rect region = rect.Intersect(pp::Rect(
-          pp::Point(), pp::Size(plugin_size_.width(), first_page_ypos)));
-      ready->push_back(PaintManager::ReadyRect(region, image_data_, false));
-      FillRect(region, background_color_);
-    }
-
     for (size_t j = 0; j < background_parts_.size(); ++j) {
       pp::Rect intersection = background_parts_[j].location.Intersect(rect);
       if (!intersection.IsEmpty()) {
@@ -1153,7 +1137,8 @@ void OutOfProcessInstance::DocumentLoadComplete(int page_count) {
 
   pp::PDF::SetContentRestriction(this, content_restrictions);
 
-  uma_.HistogramCustomCounts("PDF.PageCount", page_count, 1, 1000000, 50);
+  uma_.HistogramCustomCounts("PDF.PageCount", page_count,
+                             1, 1000000, 50);
 }
 
 void OutOfProcessInstance::RotateClockwise() {
@@ -1299,10 +1284,10 @@ void OutOfProcessInstance::OnGeometryChanged(double old_zoom,
     available_area_.Offset((available_area_.width() - doc_width) / 2, 0);
     available_area_.set_width(doc_width);
   }
-  int bottom_of_document =
-      GetDocumentPixelHeight() + (top_toolbar_height_ * device_scale_);
-  if (bottom_of_document < available_area_.height())
-    available_area_.set_height(bottom_of_document);
+  int doc_height = GetDocumentPixelHeight();
+  if (doc_height < available_area_.height()) {
+    available_area_.set_height(doc_height);
+  }
 
   CalculateBackgroundParts();
   engine_->PageOffsetUpdated(available_area_.point());
@@ -1428,9 +1413,8 @@ pp::FloatPoint OutOfProcessInstance::BoundScrollOffsetToDocument(
     const pp::FloatPoint& scroll_offset) {
   float max_x = document_size_.width() * zoom_ - plugin_dip_size_.width();
   float x = std::max(std::min(scroll_offset.x(), max_x), 0.0f);
-  float min_y = -top_toolbar_height_;
   float max_y = document_size_.height() * zoom_ - plugin_dip_size_.height();
-  float y = std::max(std::min(scroll_offset.y(), max_y), min_y);
+  float y = std::max(std::min(scroll_offset.y(), max_y), 0.0f);
   return pp::FloatPoint(x, y);
 }
 
diff --git a/pdf/out_of_process_instance.h b/pdf/out_of_process_instance.h
index 1215f19..8a3de66 100644
--- a/pdf/out_of_process_instance.h
+++ b/pdf/out_of_process_instance.h
@@ -333,10 +333,6 @@ class OutOfProcessInstance : public pp::Instance,
   // The background color of the PDF viewer.
   uint32 background_color_;
 
-  // The blank space above the first page of the document reserved for the
-  // toolbar.
-  int top_toolbar_height_;
-
   DISALLOW_COPY_AND_ASSIGN(OutOfProcessInstance);
 };
 
diff --git a/pdf/pdf_engine.h b/pdf/pdf_engine.h
index 24c69b5..857db88 100644
--- a/pdf/pdf_engine.h
+++ b/pdf/pdf_engine.h
@@ -233,9 +233,6 @@ class PDFEngine {
   virtual pp::Rect GetPageRect(int index) = 0;
   // Gets the rectangle of the page excluding any additional areas.
   virtual pp::Rect GetPageContentsRect(int index) = 0;
-  // Returns a page's rect in screen coordinates, as well as its surrounding
-  // border areas and bottom separator.
-  virtual pp::Rect GetPageScreenRect(int page_index) const = 0;
   // Gets the offset of the vertical scrollbar from the top in document
   // coordinates.
   virtual int GetVerticalScrollbarYPosition() = 0;
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.