Fix VS 2015 64-bit truncation warning

gpu/gles2_conform_support/egl/egl.cc

Index: gpu/gles2_conform_support/egl/egl.cc
diff --git a/gpu/gles2_conform_support/egl/egl.cc b/gpu/gles2_conform_support/egl/egl.cc
index 3a39728c3762e88d2619df6c8b6d5805cc1d9bd4..b439b1eb09866e2b6623837f8d349b909f02c9ef 100644
--- a/gpu/gles2_conform_support/egl/egl.cc
+++ b/gpu/gles2_conform_support/egl/egl.cc
@@ -126,7 +126,7 @@ EGLAPI EGLBoolean EGLAPIENTRY eglInitialize(EGLDisplay dpy,
     for (size_t i = 0; i < args.size(); ++i) {
       argv[i] = args[i].c_str();
     }
-    base::CommandLine::Init(args.size(), argv.get());
+    base::CommandLine::Init(static_cast<int>(args.size()), argv.get());
     base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
     if (!command_line->HasSwitch(switches::kDisableGpuDriverBugWorkarounds)) {
       gpu::ApplyGpuDriverBugWorkarounds(command_line);