Compute pageScaleFactor on page so that fixed layout page fits width of window.

content/renderer/render_view.h

Index: content/renderer/render_view.h
diff --git a/content/renderer/render_view.h b/content/renderer/render_view.h
index ac81413ebfa4503ee2422e736583a92953ca962d..09c3090aec74df626a3e01ec37a21146a289f1c3 100644
--- a/content/renderer/render_view.h
+++ b/content/renderer/render_view.h
@@ -150,6 +150,7 @@ struct WebFindOptions;
 struct WebMediaPlayerAction;
 struct WebPluginParams;
 struct WebPoint;
+struct WebRect;
 struct WebWindowFeatures;
 }
 
@@ -371,6 +372,7 @@ class RenderView : public RenderWidget,
   virtual WebKit::WebExternalPopupMenu* createExternalPopupMenu(
       const WebKit::WebPopupMenuInfo& popup_menu_info,
       WebKit::WebExternalPopupMenuClient* popup_menu_client);
+  virtual WebKit::WebRect getDeviceRect() const;
   virtual WebKit::WebStorageNamespace* createSessionStorageNamespace(
       unsigned quota);
   virtual void didAddMessageToConsole(
@@ -633,6 +635,8 @@ class RenderView : public RenderWidget,
       TransportDIB** dib,
       gfx::Rect* location,
       gfx::Rect* clip);
+  virtual gfx::Size GetContentSize();
+  virtual float GetPageScaleFactor();
   virtual gfx::Point GetScrollOffset();
   virtual void DidHandleKeyEvent();
   virtual void DidHandleMouseEvent(const WebKit::WebMouseEvent& event);
@@ -885,6 +889,16 @@ class RenderView : public RenderWidget,
   // Check whether the preferred size has changed.
   void CheckPreferredSize();
 
+  // Return the offset, restricted to the document area at the given scale.
+  // (The offset is in the coordinate space of the new scale).
+  gfx::Point ClampOffsetAtScale(const gfx::Point& offset, float scale);
+
+  // Get the scale when the document is fully zoomed out (minimum scale).
+  float ComputeOverviewScale(gfx::Size content_size);
+
+  // Compute the scale within min/max limits.
+  float ComputeScaleWithinLimits(float scale);
+
   // This callback is triggered when DownloadFavicon completes, either
   // succesfully or with a failure. See DownloadFavicon for more
   // details.
@@ -925,6 +939,18 @@ class RenderView : public RenderWidget,
                                    const WebKit::WebURLError& error,
                                    bool replace);
 
+  // Scales current scroll offset to a new factor.
+  void SetPageScaleFactor(float scale);
+
+  // Moves to the scroll offset (should be provided in the new scale, not the
+  // previous one).
+  void SetPageScaleFactorAndScroll(float scale, const gfx::Point& offset);
+
+  // Keeps Keeps the anchor (in window coordinates) in a stable position on the

[jam, 2011/09/02 17:11:41]

nit Keeps Keeps

[Fady Samuel, 2011/09/08 23:46:39]

Done.

+  // screen.
+  void SetPageScaleFactorWithAnchor(float scale,
+                                    const gfx::Point& window_anchor);
+
   // Starts nav_state_sync_timer_ if it isn't already running.
   void StartNavStateSyncTimerIfNecessary();
 
@@ -938,12 +964,17 @@ class RenderView : public RenderWidget,
   // selection handles in sync with the webpage.
   void SyncSelectionIfRequired();
 
+  // If not already initialized, initialize the scale to the overview scale.
+  bool TryInitializeScale();
+
 #if defined(OS_POSIX) && !defined(OS_MACOSX)
   void UpdateFontRenderingFromRendererPrefs();
 #else
   void UpdateFontRenderingFromRendererPrefs() {}
 #endif
 
+  void UpdatePageScale(gfx::Size new_content_size);
+
   // Update the target url and tell the browser that the target URL has changed.
   // If |url| is empty, show |fallback_url|.
   void UpdateTargetURL(const GURL& url, const GURL& fallback_url);
@@ -1177,6 +1208,13 @@ class RenderView : public RenderWidget,
 
   DevToolsAgent* devtools_agent_;
 
+  // Scaling and Fixed Layout --------------------------------------------------
+
+  // viewport scale related fields.
+  bool user_scalable_;
+  float minimum_scale_;
+  float maximum_scale_;

[jamesr, 2011/09/02 17:43:09]

why are these member variables? from what I can tell they are always set to the
defaults

[Fady Samuel, 2011/09/08 23:46:39]

These will be used in an upcoming patch once the viewport meta tag is enabled.

+
   // Misc ----------------------------------------------------------------------
 
   // The current and pending file chooser completion objects. If the queue is