Fix Renderer11 signed/unsigned warning in 32-bit.

Change-Id: I1e11f54b0ae245cdd7e090ab0748821738ad6314
Reviewed-on: https://chromium-review.googlesource.com/218761
Reviewed-by: Geoff Lang <geofflang@chromium.org>
Tested-by: Jamie Madill <jmadill@chromium.org>
diff --git a/src/libGLESv2/renderer/d3d/d3d11/Renderer11.cpp b/src/libGLESv2/renderer/d3d/d3d11/Renderer11.cpp
index b12a654..c59c54b 100644
--- a/src/libGLESv2/renderer/d3d/d3d11/Renderer11.cpp
+++ b/src/libGLESv2/renderer/d3d/d3d11/Renderer11.cpp
@@ -1568,17 +1568,17 @@
     mRenderTargetDescInitialized = false;
 
     ASSERT(mForceSetVertexSamplerStates.size() == mCurVertexSRVs.size());
-    for (int i = 0; i < mForceSetVertexSamplerStates.size(); i++)
+    for (size_t vsamplerId = 0; vsamplerId < mForceSetVertexSamplerStates.size(); ++vsamplerId)
     {
-        mForceSetVertexSamplerStates[i] = true;
-        mCurVertexSRVs[i] = NULL;
+        mForceSetVertexSamplerStates[vsamplerId] = true;
+        mCurVertexSRVs[vsamplerId] = NULL;
     }
 
     ASSERT(mForceSetPixelSamplerStates.size() == mCurPixelSRVs.size());
-    for (int i = 0; i < mForceSetPixelSamplerStates.size(); i++)
+    for (size_t fsamplerId = 0; fsamplerId < mForceSetPixelSamplerStates.size(); ++fsamplerId)
     {
-        mForceSetPixelSamplerStates[i] = true;
-        mCurPixelSRVs[i] = NULL;
+        mForceSetPixelSamplerStates[fsamplerId] = true;
+        mCurPixelSRVs[fsamplerId] = NULL;
     }
 
     mForceSetBlendState = true;