cmake: Update target platform versions (issue #2109)

- macOS: Allow selection of 10.11 SDK and set target version to 10.9 SDK.
- Windows: Set target version to Windows 7.

cmake/cef_variables.cmake.in

@@ -268,7 +268,7 @@ if(OS_MACOSX)
 
   # Find the newest available base SDK.
   execute_process(COMMAND xcode-select --print-path OUTPUT_VARIABLE XCODE_PATH OUTPUT_STRIP_TRAILING_WHITESPACE)
-  foreach(OS_VERSION 10.10 10.9 10.8 10.7)
+  foreach(OS_VERSION 10.11 10.10 10.9)
     set(SDK "${XCODE_PATH}/Platforms/MacOSX.platform/Developer/SDKs/MacOSX${OS_VERSION}.sdk")
     if(NOT "${CMAKE_OSX_SYSROOT}" AND EXISTS "${SDK}" AND IS_DIRECTORY "${SDK}")
       set(CMAKE_OSX_SYSROOT ${SDK})
@@ -276,7 +276,7 @@ if(OS_MACOSX)
   endforeach()
 
   # Target SDK.
-  set(CEF_TARGET_SDK               "10.7")
+  set(CEF_TARGET_SDK               "10.9")
   list(APPEND CEF_COMPILER_FLAGS
     -mmacosx-version-min=${CEF_TARGET_SDK}
   )
@@ -376,7 +376,7 @@ if(OS_WINDOWS)
   list(APPEND CEF_COMPILER_DEFINES
     WIN32 _WIN32 _WINDOWS             # Windows platform
     UNICODE _UNICODE                  # Unicode build
-    WINVER=0x0602 _WIN32_WINNT=0x602  # Targeting Windows 8
+    WINVER=0x0601 _WIN32_WINNT=0x601  # Targeting Windows 7
     NOMINMAX                          # Use the standard's templated min/max
     WIN32_LEAN_AND_MEAN               # Exclude less common API declarations
     _HAS_EXCEPTIONS=0                 # Disable exceptions