remove unneeded device:lockpixels

src/core/SkBitmapDevice.cpp

Index: src/core/SkBitmapDevice.cpp
diff --git a/src/core/SkBitmapDevice.cpp b/src/core/SkBitmapDevice.cpp
index 5b2fc38e321cc48f6e6aff68f822e92fd8bcf727..995b427697f5ff6ca3ae632da3a9af3a5be9d44e 100644
--- a/src/core/SkBitmapDevice.cpp
+++ b/src/core/SkBitmapDevice.cpp
@@ -120,18 +120,6 @@ SkBaseDevice* SkBitmapDevice::onCreateDevice(const CreateInfo& cinfo, const SkPa
     return SkBitmapDevice::Create(cinfo.fInfo, &leaky);
 }
 
-void SkBitmapDevice::lockPixels() {
-    if (fBitmap.lockPixelsAreWritable()) {
-        fBitmap.lockPixels();
-    }
-}
-
-void SkBitmapDevice::unlockPixels() {
-    if (fBitmap.lockPixelsAreWritable()) {
-        fBitmap.unlockPixels();
-    }
-}
-
 const SkBitmap& SkBitmapDevice::onAccessBitmap() {
     return fBitmap;
 }
@@ -172,6 +160,20 @@ bool SkBitmapDevice::onReadPixels(const SkImageInfo& dstInfo, void* dstPixels, s
     return fBitmap.readPixels(dstInfo, dstPixels, dstRowBytes, x, y);
 }
 
+void SkBitmapDevice::onAttachToCanvas(SkCanvas* canvas) {
+    INHERITED::onAttachToCanvas(canvas);
+    if (fBitmap.lockPixelsAreWritable()) {
+        fBitmap.lockPixels();
+    }
+}
+
+void SkBitmapDevice::onDetachFromCanvas() {
+    INHERITED::onDetachFromCanvas();
+    if (fBitmap.lockPixelsAreWritable()) {
+        fBitmap.unlockPixels();
+    }
+}
+
 ///////////////////////////////////////////////////////////////////////////////
 
 void SkBitmapDevice::drawPaint(const SkDraw& draw, const SkPaint& paint) {