Update libchromiumcontent for Windows support

* vendor/libchromiumcontent e70a88f...4aae27b (2):
  > Merge pull request #11 from brightray/windows-build
  > Merge pull request #10 from brightray/windows-scripts
Add prerequisites to the README
Ensure consistent line endings in all files
Make script/build actually run gyp on Windows

We don't yet build, but we're getting closer.
Ignore .sln/.vcxproj files created by gyp
Use MSBuild to build on Windows
Make sure sk_stdint.h is in the include path
Add some build defaults for Windows

These came from Chromium's build/common.gypi file.
MSVC doesn't allow `override` on destructors
Use FILE_PATH_LITERAL to fix build errors
Fix Windows build error about passing std::string to base::FilePath::Append
Don't use range-based for loops

VS2010 doesn't support them :-(
Ignore files created by Visual Studio
Merge pull request #16 from brightray/windows-build

Get a basic Windows build working