Revert of Use an image generator to back SkPictureShader tiles.

src/core/SkPictureShader.cpp

Index: src/core/SkPictureShader.cpp
diff --git a/src/core/SkPictureShader.cpp b/src/core/SkPictureShader.cpp
index 1453aee0a8658fb34a2d4351da2f7fb1f3d974b0..cf0157c2a59fd880b4f9f3fe65bfd25a0b8e25cc 100644
--- a/src/core/SkPictureShader.cpp
+++ b/src/core/SkPictureShader.cpp
@@ -10,7 +10,6 @@
 #include "SkBitmap.h"
 #include "SkBitmapProcShader.h"
 #include "SkCanvas.h"
-#include "SkImageGenerator.h"
 #include "SkMatrixUtils.h"
 #include "SkPicture.h"
 #include "SkReadBuffer.h"
@@ -22,50 +21,6 @@
 
 namespace {
 static unsigned gBitmapSkaderKeyNamespaceLabel;
-
-class PictureImageGenerator : public SkImageGenerator {
-public:
-    PictureImageGenerator(const SkPicture* picture,
-                          const SkRect& pictureTile,
-                          const SkISize& tileSize)
-        : fPicture(SkRef(picture))
-        , fPictureTile(pictureTile)
-        , fRasterTileInfo(SkImageInfo::MakeN32Premul(tileSize)) {}
-
-protected:
-    virtual bool onGetInfo(SkImageInfo *info) SK_OVERRIDE {
-        *info = fRasterTileInfo;
-        return true;
-    }
-
-    virtual Result onGetPixels(const SkImageInfo& info, void *pixels, size_t rowBytes,
-                             SkPMColor ctable[], int *ctableCount) SK_OVERRIDE {
-        if (info != fRasterTileInfo || SkToBool(ctable) || SkToBool(ctableCount)) {
-            return kInvalidConversion;
-        }
-
-        SkSize tileScale = SkSize::Make(SkIntToScalar(info.width()) / fPictureTile.width(),
-                                        SkIntToScalar(info.height()) / fPictureTile.height());
-        SkBitmap tileBitmap;
-        if (!tileBitmap.installPixels(info, pixels, rowBytes)) {
-            return kInvalidParameters;
-        }
-        tileBitmap.eraseColor(SK_ColorTRANSPARENT);
-
-        // Always disable LCD text, since we can't assume our image will be opaque.
-        SkCanvas tileCanvas(tileBitmap, SkSurfaceProps(0, kUnknown_SkPixelGeometry));
-        tileCanvas.scale(tileScale.width(), tileScale.height());
-        tileCanvas.translate(-fPictureTile.x(), -fPictureTile.y());
-        tileCanvas.drawPicture(fPicture);
-
-        return kSuccess;
-    }
-
-private:
-    SkAutoTUnref<const SkPicture> fPicture;
-    const SkRect                  fPictureTile;
-    const SkImageInfo             fRasterTileInfo;
-};
 
 struct BitmapShaderKey : public SkResourceCache::Key {
 public:
@@ -126,11 +81,23 @@
 
         result->reset(SkRef(rec.fShader.get()));
 
-        // The bitmap shader is backed by an image generator, thus it can always re-generate its
-        // pixels if discarded.
-        return true;
+        SkBitmap tile;
+        rec.fShader.get()->asABitmap(&tile, NULL, NULL);
+        // FIXME: this doesn't protect the pixels from being discarded as soon as we unlock.
+        // Should be handled via a pixel ref generator instead
+        // (https://code.google.com/p/skia/issues/detail?id=3220).
+        SkAutoLockPixels alp(tile, true);
+        return tile.getPixels() != NULL;
     }
 };
+
+static bool cache_try_alloc_pixels(SkBitmap* bitmap) {
+    SkBitmap::Allocator* allocator = SkResourceCache::GetAllocator();
+
+    return NULL != allocator
+        ? allocator->allocPixelRef(bitmap, NULL)
+        : bitmap->tryAllocPixels();
+}
 
 } // namespace
 
@@ -141,6 +108,10 @@
     , fTile(tile ? *tile : picture->cullRect())
     , fTmx(tmx)
     , fTmy(tmy) {
+}
+
+SkPictureShader::~SkPictureShader() {
+    fPicture->unref();
 }
 
 SkPictureShader* SkPictureShader::Create(const SkPicture* picture, TileMode tmx, TileMode tmy,
@@ -217,10 +188,18 @@
 
     if (!SkResourceCache::Find(key, BitmapShaderRec::Visitor, &tileShader)) {
         SkBitmap bm;
-        if (!SkInstallDiscardablePixelRef(SkNEW_ARGS(PictureImageGenerator,
-                                                     (fPicture, fTile, tileSize)), &bm)) {
+        bm.setInfo(SkImageInfo::MakeN32Premul(tileSize));
+        if (!cache_try_alloc_pixels(&bm)) {
             return NULL;
         }
+        bm.eraseColor(SK_ColorTRANSPARENT);
+
+        // Always disable LCD text, since we can't assume our image will be opaque.
+        SkCanvas canvas(bm, SkSurfaceProps(0, kUnknown_SkPixelGeometry));
+
+        canvas.scale(tileScale.width(), tileScale.height());
+        canvas.translate(-fTile.x(), -fTile.y());
+        canvas.drawPicture(fPicture);
 
         SkMatrix shaderMatrix = this->getLocalMatrix();
         shaderMatrix.preScale(1 / tileScale.width(), 1 / tileScale.height());
@@ -301,10 +280,10 @@
     };
 
     str->appendf("PictureShader: [%f:%f:%f:%f] ",
-                 fPicture->cullRect().fLeft,
-                 fPicture->cullRect().fTop,
-                 fPicture->cullRect().fRight,
-                 fPicture->cullRect().fBottom);
+                 fPicture ? fPicture->cullRect().fLeft : 0,
+                 fPicture ? fPicture->cullRect().fTop : 0,
+                 fPicture ? fPicture->cullRect().fRight : 0,
+                 fPicture ? fPicture->cullRect().fBottom : 0);
 
     str->appendf("(%s, %s)", gTileModeName[fTmx], gTileModeName[fTmy]);