Start cleaning up 64bit Win warnings

src/gpu/GrGpu.cpp

Index: src/gpu/GrGpu.cpp
===================================================================
--- src/gpu/GrGpu.cpp	(revision 11758)
+++ src/gpu/GrGpu.cpp	(working copy)
@@ -183,12 +183,12 @@
     return this->onWrapBackendRenderTarget(desc);
 }
 
-GrVertexBuffer* GrGpu::createVertexBuffer(uint32_t size, bool dynamic) {
+GrVertexBuffer* GrGpu::createVertexBuffer(size_t size, bool dynamic) {
     this->handleDirtyContext();
     return this->onCreateVertexBuffer(size, dynamic);
 }
 
-GrIndexBuffer* GrGpu::createIndexBuffer(uint32_t size, bool dynamic) {
+GrIndexBuffer* GrGpu::createIndexBuffer(size_t size, bool dynamic) {
     this->handleDirtyContext();
     return this->onCreateIndexBuffer(size, dynamic);
 }