Expose webkit scaling factor before calling WebFrame::PrintPage()

Rev 12100 changed the way that we spool and render printed output, most notably introducing use of the PrintContext class.  The existing PrintContext::spoolPage() method applies a webkit scaling factor before rendering output to the graphics context.  ChromePrintContext::spoolPage() (in webframe_impl.cc), which is used by chromium instead of PrintContext::spoolPage(), does not apply this scaling factor, but instead eventually returns the scaling factor via WebFrame::PrintPage().  This is a problem for the Chromium Embedded Framework (CEF) because, unlike chromium, the CEF renders directly to the printer device context.  It is therefore important for CEF that we retrieve and apply the webkit scaling factor before calling PrintPage().  In order to support this capability the following adds a WebFrame::GetPrintPageShrink() method.

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=14639

[Marshall Greenblatt, 2009-04-27 16:09:18]

Please review this patch set.

[M-A Ruel, 2009-04-27 18:41:12]

lgtm. I'll check-in with the modifications and updating the copyright dates.

http://codereview.chromium.org/99058/diff/1001/1002
File webkit/glue/webframe.h (right):

http://codereview.chromium.org/99058/diff/1001/1002#newcode383
Line 383: virtual float GetPrintPageShrink(int page) =0;
spacing is "...) = 0;"

http://codereview.chromium.org/99058/diff/1001/1004
File webkit/glue/webframe_impl.cc (right):

http://codereview.chromium.org/99058/diff/1001/1004#newcode1893
Line 1893: if (!print_context_.get() || page < 0 || !frame() ||
!frame()->document()) {
I don't think it's worth looking at frame() or frame()->document() here.