Enable and fix the -Wshorten-64-to-32

BUG=angleproject:635

Change-Id: If09014508d5f4dfeb17ac946672a76a98b8ad175
Reviewed-on: https://chromium-review.googlesource.com/316580
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>
Tryjob-Request: Corentin Wallez <cwallez@chromium.org>
Tested-by: Corentin Wallez <cwallez@chromium.org>
diff --git a/src/libANGLE/renderer/gl/VertexArrayGL.cpp b/src/libANGLE/renderer/gl/VertexArrayGL.cpp
index 7085663..255b41f 100644
--- a/src/libANGLE/renderer/gl/VertexArrayGL.cpp
+++ b/src/libANGLE/renderer/gl/VertexArrayGL.cpp
@@ -232,7 +232,7 @@
     ASSERT(mAttributesNeedStreaming.any());
 
     const auto &attribs = mData.getVertexAttributes();
-    for (unsigned int idx : angle::IterateBitSet(mAttributesNeedStreaming & activeAttributesMask))
+    for (auto idx : angle::IterateBitSet(mAttributesNeedStreaming & activeAttributesMask))
     {
         const auto &attrib = attribs[idx];
         ASSERT(AttributeNeedsStreaming(attrib));
@@ -292,8 +292,7 @@
         size_t curBufferOffset = bufferEmptySpace;
 
         const auto &attribs = mData.getVertexAttributes();
-        for (unsigned int idx :
-             angle::IterateBitSet(mAttributesNeedStreaming & activeAttributesMask))
+        for (auto idx : angle::IterateBitSet(mAttributesNeedStreaming & activeAttributesMask))
         {
             const auto &attrib = attribs[idx];
             ASSERT(AttributeNeedsStreaming(attrib));
@@ -334,13 +333,14 @@
             {
                 ASSERT(!attrib.normalized);
                 mFunctions->vertexAttribIPointer(
-                    idx, attrib.size, attrib.type, static_cast<GLsizei>(destStride),
+                    static_cast<GLuint>(idx), attrib.size, attrib.type,
+                    static_cast<GLsizei>(destStride),
                     reinterpret_cast<const GLvoid *>(vertexStartOffset));
             }
             else
             {
                 mFunctions->vertexAttribPointer(
-                    idx, attrib.size, attrib.type, attrib.normalized,
+                    static_cast<GLuint>(idx), attrib.size, attrib.type, attrib.normalized,
                     static_cast<GLsizei>(destStride),
                     reinterpret_cast<const GLvoid *>(vertexStartOffset));
             }