Revert "Fix and enable warning C4244 (Conversion from 'type1' to 'type2', possible loss of data)"

Causing a build failure on Mac/Clang:

./Tokenizer.cpp:551:7: error: extra tokens at end of #else directive [-Werror,-Wextra-tokens]
#else if defined(_MSC_VER)

http://build.chromium.org/p/chromium.gpu.fyi/builders/GPU%20Mac%20Builder/builds/29136

This reverts commit 3b26e231d99154814eb428f75a67bbe7a21adadc.

Change-Id: I2d11ddcc18130d908fd2ec3d6f5ab890cfccd5e7
Reviewed-on: https://chromium-review.googlesource.com/264983
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Tested-by: Jamie Madill <jmadill@chromium.org>
diff --git a/util/shader_utils.cpp b/util/shader_utils.cpp
index 4a71017..9bc41ae 100644
--- a/util/shader_utils.cpp
+++ b/util/shader_utils.cpp
@@ -22,7 +22,7 @@
     std::string result;
 
     stream.seekg(0, std::ios::end);
-    result.reserve(static_cast<unsigned int>(stream.tellg()));
+    result.reserve(stream.tellg());
     stream.seekg(0, std::ios::beg);
 
     result.assign((std::istreambuf_iterator<char>(stream)), std::istreambuf_iterator<char>());