Have GrSurfaceProxys and GrGpuResources draw from the same pool of unique ids

The idea here is that, for wrapped Proxy objects, we want the uniqueID to reflect that of the wrapped object. For this to work the IDs for the non-wrapped versions can't conflict with GrGpuResource's pool of IDs.

Split off of: https://codereview.chromium.org/2215323003/ (Start using RenderTargetProxy (omnibus))

GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2301523003

Review-Url: https://codereview.chromium.org/2301523003
diff --git a/src/gpu/gl/GrGLRenderTarget.cpp b/src/gpu/gl/GrGLRenderTarget.cpp
index d9bbb73..f6ad3ba 100644
--- a/src/gpu/gl/GrGLRenderTarget.cpp
+++ b/src/gpu/gl/GrGLRenderTarget.cpp
@@ -190,7 +190,7 @@
         // Due to this resource having both a texture and a renderbuffer component, dump as
         // skia/gpu_resources/resource_#/renderbuffer
         SkString dumpName("skia/gpu_resources/resource_");
-        dumpName.appendS32(this->getUniqueID());
+        dumpName.appendS32(this->uniqueID());
         dumpName.append("/renderbuffer");
 
         traceMemoryDump->dumpNumericValue(dumpName.c_str(), "size", "bytes", size);