Enable automatic rescaling in bench_pictures

bench_pictures with "--device gpu" is failing because we're trying to allocate
too much GPU memory.  Move the recently-added scaling code into picture_utils
and share it between render_pictures and bench_pictures.
Review URL: https://codereview.appspot.com/6495125

git-svn-id: http://skia.googlecode.com/svn/trunk@5543 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/tools/render_pictures_main.cpp b/tools/render_pictures_main.cpp
index 87d5d4b..7d54516 100644
--- a/tools/render_pictures_main.cpp
+++ b/tools/render_pictures_main.cpp
@@ -89,27 +89,6 @@
     }
 }
 
-static bool area_too_big(int w, int h, SkISize* newSize) {
-    // just a guess, based on what seems to fail on smaller android devices
-    static const int64_t kMaxAreaForMemory = 16 * 1024 * 1024;
-
-    if ((int64_t)w * h > kMaxAreaForMemory) {
-        do {
-            w >>= 1;
-            h >>= 1;
-        } while ((int64_t)w * h > kMaxAreaForMemory);
-        if (0 == w) {
-            w = 1;
-        }
-        if (0 == h) {
-            h = 1;
-        }
-        newSize->set(w, h);
-        return true;
-    }
-    return false;
-}
-
 static void render_picture(const SkString& inputPath, const SkString& outputDir,
                            sk_tools::PictureRenderer& renderer) {
     SkString inputFilename;
@@ -122,32 +101,16 @@
         return;
     }
 
-    SkPicture picture(&inputStream);
+    SkPicture* picture = SkNEW_ARGS(SkPicture, (&inputStream));
+    SkAutoTUnref<SkPicture> aur(picture);
 
-    SkDebugf("drawing... [%i %i] %s\n", picture.width(), picture.height(),
+    SkDebugf("drawing... [%i %i] %s\n", picture->width(), picture->height(),
              inputPath.c_str());
 
+    // rescale to avoid memory issues allocating a very large offscreen
+    sk_tools::resize_if_needed(&aur);
 
-    // rescale to avoid memory issues allcoating a very large offscreen
-    SkPicture* pic = &picture;
-    SkISize newSize;
-    SkAutoUnref aur(NULL);
-
-    if (area_too_big(picture.width(), picture.height(), &newSize)) {
-        pic = new SkPicture;
-        aur.reset(pic);
-
-        SkCanvas* canvas = pic->beginRecording(newSize.width(), newSize.height());
-        SkScalar scale = SkIntToScalar(newSize.width()) / picture.width();
-        canvas->scale(scale, scale);
-        canvas->drawPicture(picture);
-        pic->endRecording();
-
-        SkDebugf("... rescaling to [%d %d] to avoid overly large allocations\n",
-                 newSize.width(), newSize.height());
-    }
-
-    renderer.init(pic);
+    renderer.init(aur);
 
     renderer.render(true);