try adding flag to allow lcd text even in a layer

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 "SkBitmapDevice.h"
 #include "SkCanvas.h"
 #include "SkCanvasPriv.h"
@@ skipping 1122 matching lines @@
 int SkCanvas::saveLayer(const SkRect* bounds, const SkPaint* paint, SaveFlags flags) {
     if (gIgnoreSaveLayerBounds) {
         bounds = nullptr;
     }
     SaveLayerStrategy strategy = this->willSaveLayer(bounds, paint, flags);
     fSaveCount += 1;
     this->internalSaveLayer(bounds, paint, flags, strategy);
     return this->getSaveCount() - 1;
 }
 
+int SkCanvas::saveLayerPreserveLCDTextRequests(const SkRect* bounds, const SkPaint* paint) {
+    unsigned flags = kARGB_ClipLayer_SaveFlag | kPreserveLCDText_PrivateSaveFlag;
+    return this->saveLayer(bounds, paint, (SaveFlags)flags);
+}
+
+
 void SkCanvas::internalSaveLayer(const SkRect* bounds, const SkPaint* paint, SaveFlags flags,
                                  SaveLayerStrategy strategy) {
 #ifndef SK_SUPPORT_LEGACY_CLIPTOLAYERFLAG
     flags |= kClipToLayer_SaveFlag;
 #endif
 
     // do this before we create the layer. We don't call the public save() since
     // that would invoke a possibly overridden virtual
     this->internalSave();
 
@@ skipping 23 matching lines @@
                         isOpaque ? kOpaque_SkAlphaType : kPremul_SkAlphaType);
 
     SkBaseDevice* device = this->getTopDevice();
     if (nullptr == device) {
         SkDebugf("Unable to find device for layer.");
         return;
     }
 
     bool forceSpriteOnRestore = false;
     {
+        const bool preserveLCDText = kOpaque_SkAlphaType == info.alphaType() ||
+                                     SkToBool(flags & kPreserveLCDText_PrivateSaveFlag);
         const SkBaseDevice::TileUsage usage = SkBaseDevice::kNever_TileUsage;
-        const SkBaseDevice::CreateInfo createInfo = SkBaseDevice::CreateInfo(info, usage, geo);
+        const SkBaseDevice::CreateInfo createInfo = SkBaseDevice::CreateInfo(info, usage, geo,
+                                                                            preserveLCDText, false);
         SkBaseDevice* newDev = device->onCreateDevice(createInfo, paint);
         if (nullptr == newDev) {
             // If onCreateDevice didn't succeed, try raster (e.g. PDF couldn't handle the paint)
             const SkSurfaceProps surfaceProps(fProps.flags(), createInfo.fPixelGeometry);
             newDev = SkBitmapDevice::Create(createInfo.fInfo, surfaceProps);
             if (nullptr == newDev) {
                 SkErrorInternals::SetError(kInternalError_SkError,
                                            "Unable to create device for layer.");
                 return;
             }
@@ skipping 1806 matching lines @@
     }
 
     if (matrix) {
         canvas->concat(*matrix);
     }
 }
 
 SkAutoCanvasMatrixPaint::~SkAutoCanvasMatrixPaint() {
     fCanvas->restoreToCount(fSaveCount);
 }