Fix build warnings in x64.

A std::min/max with size_t and unsigned int.

Popped up in f98e63a54b8a2.

BUG=

Change-Id: I25f26ddbe7fb333f895be8a8dce3d3d73044c3f9
Reviewed-on: https://chromium-review.googlesource.com/200484
Reviewed-by: Geoff Lang <geofflang@chromium.org>
Tested-by: Jamie Madill <jmadill@chromium.org>
diff --git a/src/libGLESv2/renderer/d3d11/InputLayoutCache.cpp b/src/libGLESv2/renderer/d3d11/InputLayoutCache.cpp
index 6f53fd4..7092dc5 100644
--- a/src/libGLESv2/renderer/d3d11/InputLayoutCache.cpp
+++ b/src/libGLESv2/renderer/d3d11/InputLayoutCache.cpp
@@ -207,8 +207,8 @@
             vertexOffset != mCurrentVertexOffsets[i])
         {
             dirtyBuffers = true;
-            minDiff = std::min(minDiff, i);
-            maxDiff = std::max(maxDiff, i);
+            minDiff = std::min(minDiff, static_cast<size_t>(i));
+            maxDiff = std::max(maxDiff, static_cast<size_t>(i));
 
             mCurrentBuffers[i] = buffer;
             mCurrentVertexStrides[i] = vertexStride;