Revise SVD code to remove arctangents.

tests/Matrix44Test.cpp

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "Test.h"
 #include "SkMatrix44.h"
 
@@ skipping 495 matching lines @@
     rot.setRotateDegreesAbout(0, 0, -1, 90);
     mat.postConcat(rot);
     mat.postTranslate(1.0e-12, 1.0e-12, 1.0e-12);
     REPORTER_ASSERT(reporter, mat.invert(NULL));
     mat.invert(&inverse);
     iden1.setConcat(mat, inverse);
     REPORTER_ASSERT(reporter, is_identity(iden1));
 
     // test mixed-valued matrix inverse
     mat.reset();
-    mat.setScale(1.0e-10, 3.0, 1.0e+10);
+    mat.setScale(1.0e-11, 3.0, 1.0e+11);
     rot.setRotateDegreesAbout(0, 0, -1, 90);
     mat.postConcat(rot);
-    mat.postTranslate(1.0e+10, 3.0, 1.0e-10);
+    mat.postTranslate(1.0e+11, 3.0, 1.0e-11);
     REPORTER_ASSERT(reporter, mat.invert(NULL));
     mat.invert(&inverse);
     iden1.setConcat(mat, inverse);
     REPORTER_ASSERT(reporter, is_identity(iden1));
 
     // test degenerate matrix
     mat.reset();
     mat.set3x3(1.0, 1.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0, 0.0);
     REPORTER_ASSERT(reporter, !mat.invert(NULL));
 
@@ skipping 39 matching lines @@
     test_transpose(reporter);
     test_get_set_double(reporter);
     test_set_row_col_major(reporter);
     test_translate(reporter);
     test_scale(reporter);
     test_map2(reporter);
 }
 
 #include "TestClassDef.h"
 DEFINE_TESTCLASS("Matrix44", Matrix44TestClass, TestMatrix44)