[CMake fixes] Linux X11 pixel format and Windows compilation fix

cmake/CMakeLists.txt

Index: cmake/CMakeLists.txt
diff --git a/cmake/CMakeLists.txt b/cmake/CMakeLists.txt
index b375e59f453731ef58a1fc70ad12f04c0f58729f..d540bd1e61bbfb04502cbcb0f82e14780c095ea7 100644
--- a/cmake/CMakeLists.txt
+++ b/cmake/CMakeLists.txt
@@ -248,6 +248,7 @@ endif()
 
 if (WIN32)
     list (APPEND libs FontSub.lib Usp10.lib)
+    list (APPEND public_defines   "-DSK_BUILD_FOR_WIN32")

[Marco A., 2016/03/25 14:10:27]

Specifically this is needed when compiling on a Windows machine by sk_setenv()
in src/ports/SkOSEnvironment.cpp

[mtklein, 2016/03/25 14:15:12]

Let's have src/ports/SkOSEnvironment.cpp #include "SkTypes.h", which should
auto-define this.

 endif()
 
 find_package(OpenGL REQUIRED)
@@ -292,6 +293,11 @@ if (CMAKE_BUILD_TYPE STREQUAL Release)
 else()
     set (SK_RELEASE 0)
 endif()
+if (UNIX AND NOT APPLE)
+  set (SK_SAMPLES_FOR_X 1)
+else()
+  set (SK_SAMPLES_FOR_X 0)
+endif()
 configure_file ("SkUserConfig.h.in" "${userconfig_directory}/SkUserConfig.h")
 
 # skia_link_arguments.txt