Move proxyProvider and singleOwner to GrImageContext

This starts to beef up the capabilities of the GrImageContext in preparation for its future responsibilities (i.e., creating promise images w/o a recordingContext).

Note that the proxyProvider still has different behavior if it has a full context vs. a reduced context. I intend to just let this behavior remain as is.

Change-Id: Idb9d99a548ef928fc1b9dc1e5a34f74343bb0b4b
Reviewed-on: https://skia-review.googlesource.com/c/189490
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>
diff --git a/src/gpu/GrBitmapTextureMaker.cpp b/src/gpu/GrBitmapTextureMaker.cpp
index 95f1c84..89a3702 100644
--- a/src/gpu/GrBitmapTextureMaker.cpp
+++ b/src/gpu/GrBitmapTextureMaker.cpp
@@ -61,7 +61,7 @@
                 SkASSERT(proxy->origin() == kTopLeft_GrSurfaceOrigin);
                 if (fOriginalKey.isValid()) {
                     GrInstallBitmapUniqueKeyInvalidator(
-                            fOriginalKey, proxyProvider->contextUniqueID(), fBitmap.pixelRef());
+                            fOriginalKey, proxyProvider->contextID(), fBitmap.pixelRef());
                 }
                 return proxy;
             }
@@ -86,7 +86,7 @@
                 SkASSERT(proxy->getUniqueKey() == fOriginalKey);
                 proxyProvider->removeUniqueKeyFromProxy(proxy.get());
                 proxyProvider->assignUniqueKeyToProxy(fOriginalKey, mippedProxy.get());
-                GrInstallBitmapUniqueKeyInvalidator(fOriginalKey, proxyProvider->contextUniqueID(),
+                GrInstallBitmapUniqueKeyInvalidator(fOriginalKey, proxyProvider->contextID(),
                                                     fBitmap.pixelRef());
             }
             return mippedProxy;