cmake_build: support SKIA_OUT and BUILDTYPE

cmake/CMakeLists.txt

 # Boilerplate.
 cmake_minimum_required (VERSION 3.1)   # First version with CMAKE_CXX_STANDARD.
 project (skimake)
 set (CMAKE_CXX_STANDARD 11)
 
 # Default to Release mode.  We're mainly targeting Skia users, not Skia developers.
 if (NOT CMAKE_BUILD_TYPE)
     set (CMAKE_BUILD_TYPE Release)
 endif ()
 
@@ skipping 36 matching lines @@
              ../src/ports/SkFontConfigInterface_direct.cpp)
 # Alternative font managers.
 remove_srcs (../src/ports/SkFontMgr_custom*.cpp)
 # Not actually used by Skia.
 remove_srcs (../src/utils/SkThreadUtils_pthread_*.cpp)
 
 # Skia sure ships a lot of code no one uses.
 remove_srcs (../src/animator/* ../src/*nacl* ../src/svg/* ../src/views/* ../src/xml/*)
 
 # Some files only contain code in Debug mode.  This quiets down some linker warnings.
-if (NOT CMAKE_BUILD_TYPE EQUAL Debug)
+if (NOT CMAKE_BUILD_TYPE STREQUAL Debug)
     remove_srcs (../src/core/SkDebug.cpp ../src/utils/SkDumpCanvas.cpp)
 endif()
 
 # Remove OS-specific source files.
 if (NOT WIN32)
     remove_srcs(../src/*XPS*
                 ../src/*_win*.cpp
                 ../src/gpu/gl/angle/*
                 ../src/ports/SkImageDecoder_WIC.cpp
                 ../src/utils/win/*)
 endif()
 if (APPLE OR NOT UNIX)
     remove_srcs(../src/gpu/gl/glx/*
                 ../src/images/SkImageDecoder_FactoryDefault.cpp
                 ../src/ports/SkFontMgr_fontconfig*.cpp
                 ../src/*FreeType*)
 endif()
 if (NOT ANDROID)
     remove_srcs(../src/*Hwui* ../src/*android*)
 endif()
 if (NOT APPLE)
     remove_srcs(../src/*darwin*
                 ../src/ports/SkImageDecoder_CG.cpp
                 ../src/utils/mac/*
                 ../src/*mac*)
 endif()
 
 # Remove processor-specific source files.
-if (NOT CMAKE_SYSTEM_PROCESSOR EQUAL ARM)
+if (NOT CMAKE_SYSTEM_PROCESSOR STREQUAL ARM)
     remove_srcs(../src/*arm* ../src/*ARM* ../src/*neon* ../src/*NEON*)
 endif()
-if (NOT CMAKE_SYSTEM_PROCESSOR EQUAL MIPS)
+if (NOT CMAKE_SYSTEM_PROCESSOR STREQUAL MIPS)
     remove_srcs(../src/*mips* ../src/*MIPS*)
 endif()
 
 # Make our ports choices.
 remove_srcs(
     ../src/*moz*   # We're probably not Mozilla.
     ../src/gpu/GrContextFactory.cpp                  # For internal testing only.
     ../src/gpu/gl/GrGLCreateNativeInterface_none.cpp
     ../src/gpu/gl/GrGLDefaultInterface_none.cpp
     ../src/gpu/gl/SkCreatePlatformGLContext*.cpp     # For internal testing only.
@@ skipping 123 matching lines @@
     VISIBILITY_INLINES_HIDDEN true)
 
 # Experimental C API install:
 file(GLOB cheaders "../include/c/*.h")
 install(FILES ${cheaders} DESTINATION include)
 install(TARGETS skia DESTINATION lib)
 
 # Now build a simple example app that uses Skia via libskia.so.
 add_executable(example example.cpp)
 target_link_libraries(example skia ${OPENGL_LIBRARIES})