Revert of Implement approx-match support in image filter saveLayer() offscreen.

src/core/SkCanvas.cpp

 /*
  * Copyright 2008 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkCanvas.h"
 #include "SkCanvasPriv.h"
 #include "SkBitmapDevice.h"
@@ skipping 918 matching lines @@
     SkImageInfo info = SkImageInfo::MakeN32(ir.width(), ir.height(),
                         isOpaque ? kOpaque_SkAlphaType : kPremul_SkAlphaType);
 
     SkBaseDevice* device = this->getTopDevice();
     if (NULL == device) {
         SkDebugf("Unable to find device for layer.");
         return;
     }
 
     SkBaseDevice::TileUsage usage = SkBaseDevice::kNever_TileUsage;
+#if 1
+    // this seems needed for current GMs, but makes us draw slower on the GPU
+    // Related to https://code.google.com/p/skia/issues/detail?id=3519 ?
+    //
+    if (paint && paint->getImageFilter()) {
+        usage = SkBaseDevice::kPossible_TileUsage;
+    }
+#endif
     device = device->onCreateDevice(SkBaseDevice::CreateInfo(info, usage, geo), paint);
     if (NULL == device) {
         SkErrorInternals::SetError( kInternalError_SkError,
                                     "Unable to create device for layer.");
         return;
     }
 
     device->setOrigin(ir.fLeft, ir.fTop);
     DeviceCM* layer = SkNEW_ARGS(DeviceCM, (device, paint, this, fConservativeRasterClip));
     device->unref();
@@ skipping 1563 matching lines @@
     }
 
     if (matrix) {
         canvas->concat(*matrix);
     }
 }
 
 SkAutoCanvasMatrixPaint::~SkAutoCanvasMatrixPaint() {
     fCanvas->restoreToCount(fSaveCount);
 }