cc: When the transform's scale is unknown, draw render surfaces at the resolution of the screen.

cc/math_util.h

 // Copyright 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CC_MATH_UTIL_H_
 #define CC_MATH_UTIL_H_
 
 #include "base/logging.h"
 #include "cc/cc_export.h"
 #include "ui/gfx/point_f.h"
@@ skipping 88 matching lines @@
     // NOTE: These functions do not do correct clipping against w = 0 plane, but they
     // correctly detect the clipped condition via the boolean clipped.
     static gfx::QuadF mapQuad(const gfx::Transform&, const gfx::QuadF&, bool& clipped);
     static gfx::PointF mapPoint(const gfx::Transform&, const gfx::PointF&, bool& clipped);
     static gfx::Point3F mapPoint(const gfx::Transform&, const gfx::Point3F&, bool& clipped);
     static gfx::QuadF projectQuad(const gfx::Transform&, const gfx::QuadF&, bool& clipped);
     static gfx::PointF projectPoint(const gfx::Transform&, const gfx::PointF&, bool& clipped);
 
     static void flattenTransformTo2d(gfx::Transform&);
 
-    static gfx::Vector2dF computeTransform2dScaleComponents(const gfx::Transform&);
+    static gfx::Vector2dF computeTransform2dScaleComponents(const gfx::Transform&, float fallbackValue);
 
     // Returns the smallest angle between the given two vectors in degrees. Neither vector is
     // assumed to be normalized.
     static float smallestAngleBetweenVectors(gfx::Vector2dF, gfx::Vector2dF);
 
     // Projects the |source| vector onto |destination|. Neither vector is assumed to be normalized.
     static gfx::Vector2dF projectVector(gfx::Vector2dF source, gfx::Vector2dF destination);
 
     // Temporary API to ease migration from gfx::Transform
     // to gfx::Transform.
     //
     // TODO(shawnsingh, vollick) we should phase out as much as possible of
     // these temporary functions, putting functionality into gfx::Transform.
     static void rotateEulerAngles(gfx::Transform*, double eulerX, double eulerY, double eulerZ);
     static gfx::Transform inverse(const gfx::Transform&);
     static gfx::Transform to2dTransform(const gfx::Transform&);
     // Note carefully: the args here are labeled as per Webcore indexing conventions.
     static gfx::Transform createGfxTransform(double m11, double m12, double m13, double m14,
                                              double m21, double m22, double m23, double m24,
                                              double m31, double m32, double m33, double m34,
                                              double m41, double m42, double m43, double m44);
 
     static gfx::Transform createGfxTransform(double a, double b, double c,
                                              double d, double e, double f);
 };
 
 } // namespace cc
 
 #endif  // CC_MATH_UTIL_H_