SkImage-backed SkPictureShader

Instead of using an explicit image generator + SkBitmap + bitmap shader,
switch to the shiny new SkImage/image generator/image shader.

R=reed@google.com

Review URL: https://codereview.chromium.org/1343153003
diff --git a/src/core/SkPictureShader.cpp b/src/core/SkPictureShader.cpp
index 906313d..6685211 100644
--- a/src/core/SkPictureShader.cpp
+++ b/src/core/SkPictureShader.cpp
@@ -7,10 +7,10 @@
 
 #include "SkPictureShader.h"
 
-#include "SkBitmap.h"
-#include "SkBitmapProcShader.h"
 #include "SkCanvas.h"
+#include "SkImageCacherator.h"
 #include "SkImageGenerator.h"
+#include "SkImageShader.h"
 #include "SkMatrixUtils.h"
 #include "SkPicture.h"
 #include "SkReadBuffer.h"
@@ -215,20 +215,26 @@
                         this->getLocalMatrix());
 
     if (!SkResourceCache::Find(key, BitmapShaderRec::Visitor, &tileShader)) {
-        SkMatrix tileMatrix;
-        tileMatrix.setRectToRect(fTile, SkRect::MakeIWH(tileSize.width(), tileSize.height()),
-                             SkMatrix::kFill_ScaleToFit);
-        SkBitmap bm;
-        if (!SkDEPRECATED_InstallDiscardablePixelRef(
-            SkImageGenerator::NewFromPicture(tileSize, fPicture, &tileMatrix, nullptr), &bm)) {
+        SkMatrix tileMatrix =
+            SkMatrix::MakeRectToRect(fTile, SkRect::MakeIWH(tileSize.width(), tileSize.height()),
+                                     SkMatrix::kFill_ScaleToFit);
+        SkAutoTUnref<SkImage> tileImage(
+            SkImage::NewFromPicture(fPicture, tileSize, &tileMatrix, nullptr));
+        if (!tileImage) {
             return nullptr;
         }
 
         SkMatrix shaderMatrix = this->getLocalMatrix();
         shaderMatrix.preScale(1 / tileScale.width(), 1 / tileScale.height());
-        tileShader.reset(CreateBitmapShader(bm, fTmx, fTmy, &shaderMatrix));
+        tileShader.reset(tileImage->newShader(fTmx, fTmy, &shaderMatrix));
 
-        SkResourceCache::Add(new BitmapShaderRec(key, tileShader.get(), bm.getSize()));
+        // The actual pixels are accounted for in the SkImage cacherator budget. Here we
+        // use a rough estimate for the related objects.
+        const size_t bytesUsed = sizeof(SkImageShader) +
+                                 sizeof(SkImage) +
+                                 sizeof(SkImageCacherator) +
+                                 sizeof(SkImageGenerator);
+        SkResourceCache::Add(new BitmapShaderRec(key, tileShader.get(), bytesUsed));
     }
 
     return tileShader.detach();