Remove unused CFX_Matrix::Shear()

Noticed whilst grepping for Shear in previous CL.

Change-Id: Ie41cefff9dafd4128907bad1143b53caddd98a90
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/65834
Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Tom Sepez <tsepez@chromium.org>
diff --git a/core/fxcrt/fx_coordinates.cpp b/core/fxcrt/fx_coordinates.cpp
index 34a0180..f76df5f 100644
--- a/core/fxcrt/fx_coordinates.cpp
+++ b/core/fxcrt/fx_coordinates.cpp
@@ -339,10 +339,6 @@
   Concat(CFX_Matrix(cosValue, sinValue, -sinValue, cosValue, 0, 0));
 }
 
-void CFX_Matrix::Shear(float fAlphaRadian, float fBetaRadian) {
-  Concat(CFX_Matrix(1, tan(fAlphaRadian), tan(fBetaRadian), 1, 0, 0));
-}
-
 void CFX_Matrix::MatchRect(const CFX_FloatRect& dest,
                            const CFX_FloatRect& src) {
   float fDiff = src.left - src.right;
diff --git a/core/fxcrt/fx_coordinates.h b/core/fxcrt/fx_coordinates.h
index 622684f..e8d1a8a 100644
--- a/core/fxcrt/fx_coordinates.h
+++ b/core/fxcrt/fx_coordinates.h
@@ -567,7 +567,6 @@
 
   void Scale(float sx, float sy);
   void Rotate(float fRadian);
-  void Shear(float fAlphaRadian, float fBetaRadian);
 
   void MatchRect(const CFX_FloatRect& dest, const CFX_FloatRect& src);