Clean up usage of SkSurfaceProps

This CL continues cleaning up Skia's usage of SkSurfaceProps. It:

  Removes the duplicate SkSurfaceProps object from SkImageFilter::Proxy.

  Removes a dispreferred ctor from SkCanvas

  Removes the initForRootLayer entry point from SkDevice (since the root device and the canvas should always have the same pixel geometry now).

Review URL: https://codereview.chromium.org/1201983006
diff --git a/src/gpu/SkGpuDevice.cpp b/src/gpu/SkGpuDevice.cpp
index a67b2c2..1603cd6 100644
--- a/src/gpu/SkGpuDevice.cpp
+++ b/src/gpu/SkGpuDevice.cpp
@@ -1229,9 +1229,7 @@
                                 SkBitmap* result, SkIPoint* offset) {
     SkASSERT(filter);
 
-    // FIXME: plumb actual surface props such that we don't have to lie about the flags here
-    //        (https://code.google.com/p/skia/issues/detail?id=3148).
-    SkImageFilter::Proxy proxy(this, SkSurfaceProps(0, this->surfaceProps().pixelGeometry()));
+    SkImageFilter::Proxy proxy(this);
 
     if (filter->canFilterImageGPU()) {
         return filter->filterImageGPU(&proxy, wrap_texture(texture, width, height),