add SkCanvas::NewRaster factory -- a very common use-case in chrome

tests/DrawPathTest.cpp

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkBitmap.h"
 #include "SkCanvas.h"
 #include "SkDashPathEffect.h"
 #include "SkSurface.h"
 #include "Test.h"
 
-static SkCanvas* new_canvas(int w, int h) {
-    SkBitmap bm;
-    bm.allocN32Pixels(w, h);
-    return new SkCanvas(bm);
-}
-
-///////////////////////////////////////////////////////////////////////////////
-
 // test that we can draw an aa-rect at coordinates > 32K (bigger than fixedpoint)
 static void test_big_aa_rect(skiatest::Reporter* reporter) {
     SkBitmap output;
     SkPMColor pixel[1];
     output.installPixels(SkImageInfo::MakeN32Premul(1, 1),
                          pixel, 4, NULL, NULL);
 
     SkSurface* surf = SkSurface::NewRasterPMColor(300, 33300);
     SkCanvas* canvas = surf->getCanvas();
 
@@ skipping 64 matching lines @@
      */
     uint32_t data[] = {
         0x419727af, 0x43011f0c, 0x41972663, 0x43011f27,
         0x419728fc, 0x43011ed4, 0x4194064b, 0x43012197
     };
 
     SkPath path;
     moveToH(&path, &data[0]);
     cubicToH(&path, &data[2]);
 
-    SkAutoTUnref<SkCanvas> canvas(new_canvas(640, 480));
+    SkAutoTUnref<SkCanvas> canvas(SkCanvas::NewRasterN32(640, 480));
 
     SkPaint paint;
     paint.setAntiAlias(true);
     canvas->drawPath(path, paint);
 }
 
 // This used to assert in debug builds (and crash writing bad memory in release)
 // because we overflowed an intermediate value (B coefficient) setting up our
 // stepper for the quadratic. Now we bias that value by 1/2 so we don't overflow
 static void test_crbug_140803() {
@@ skipping 17 matching lines @@
 static void test_inversepathwithclip() {
     SkPath path;
 
     path.moveTo(0, SkIntToScalar(20));
     path.quadTo(SkIntToScalar(10), SkIntToScalar(10),
                 SkIntToScalar(20), SkIntToScalar(20));
     path.toggleInverseFillType();
 
     SkPaint paint;
 
-    SkAutoTUnref<SkCanvas> canvas(new_canvas(640, 480));
+    SkAutoTUnref<SkCanvas> canvas(SkCanvas::NewRasterN32(640, 480));
     canvas.get()->save();
     canvas.get()->clipRect(SkRect::MakeWH(SkIntToScalar(19), SkIntToScalar(11)));
 
     paint.setAntiAlias(false);
     canvas.get()->drawPath(path, paint);
     paint.setAntiAlias(true);
     canvas.get()->drawPath(path, paint);
 
     canvas.get()->restore();
 
@@ skipping 19 matching lines @@
         This particular test/bug only applies to the float case, where the
         coordinates are very large.
      */
     SkPath path;
     path.moveTo(64, 3);
     path.quadTo(-329936, -100000000, 1153, 330003);
 
     SkPaint paint;
     paint.setAntiAlias(true);
 
-    SkAutoTUnref<SkCanvas> canvas(new_canvas(640, 480));
+    SkAutoTUnref<SkCanvas> canvas(SkCanvas::NewRasterN32(640, 480));
     canvas.get()->drawPath(path, paint);
 }
 
 static void test_crbug_140642() {
     /*
      *  We used to see this construct, and due to rounding as we accumulated
      *  our length, the loop where we apply the phase would run off the end of
      *  the array, since it relied on just -= each interval value, which did not
      *  behave as "expected". Now the code explicitly checks for walking off the
      *  end of that array.
@@ skipping 21 matching lines @@
 }
 
 static void test_bigcubic() {
     SkPath path;
     path.moveTo(64, 3);
     path.cubicTo(-329936, -100000000, -329936, 100000000, 1153, 330003);
 
     SkPaint paint;
     paint.setAntiAlias(true);
 
-    SkAutoTUnref<SkCanvas> canvas(new_canvas(640, 480));
+    SkAutoTUnref<SkCanvas> canvas(SkCanvas::NewRasterN32(640, 480));
     canvas.get()->drawPath(path, paint);
 }
 
 // we used to assert if the bounds of the device (clip) was larger than 32K
 // even when the path itself was smaller. We just draw and hope in the debug
 // version to not assert.
 static void test_giantaa() {
     const int W = 400;
     const int H = 400;
-    SkAutoTUnref<SkCanvas> canvas(new_canvas(33000, 10));
-    canvas.get()->clear(SK_ColorTRANSPARENT);
+    SkAutoTUnref<SkCanvas> canvas(SkCanvas::NewRasterN32(33000, 10));
 
     SkPaint paint;
     paint.setAntiAlias(true);
     SkPath path;
     path.addOval(SkRect::MakeXYWH(-10, -10, 20 + W, 20 + H));
     canvas.get()->drawPath(path, paint);
 }
 
 // Extremely large path_length/dash_length ratios may cause infinite looping
 // in SkDashPathEffect::filterPath() due to single precision rounding.
@@ skipping 44 matching lines @@
     test_crbug_124652();
     test_crbug_140642();
     test_crbug_140803();
     test_inversepathwithclip();
     // why?
     if (false) test_crbug131181();
     test_infinite_dash(reporter);
     test_crbug_165432(reporter);
     test_big_aa_rect(reporter);
 }