clang/win: Fix most -Wunused-function warnings in Chromium code.

chrome/app/image_pre_reader_win.cc

Index: chrome/app/image_pre_reader_win.cc
diff --git a/chrome/app/image_pre_reader_win.cc b/chrome/app/image_pre_reader_win.cc
index 6c5ef6bcb924e248b39d23d5203cac2d0a261d7e..9998a036905a03eb32e3add6572d958d2fcd4791 100644
--- a/chrome/app/image_pre_reader_win.cc
+++ b/chrome/app/image_pre_reader_win.cc
@@ -28,10 +28,8 @@ const size_t kMinHeaderBufferSize = 0x400;
 // A handy symbolic constant.
 const size_t kOneHundredPercent = 100;
 
-void StaticAssertions() {
-  COMPILE_ASSERT(kMinHeaderBufferSize >= sizeof(IMAGE_DOS_HEADER),
-                 min_header_buffer_size_at_least_as_big_as_the_dos_header);
-}
+static_assert(kMinHeaderBufferSize >= sizeof(IMAGE_DOS_HEADER),
+              "kMinHeaderBufferSize must be at least as big as the dos header");
 
 // This struct provides a deallocation functor for use with scoped_ptr<T>
 // allocated with ::VirtualAlloc().