Move GrTextContext to private interface

gyp/gpu.gypi

 # Include this gypi to include all 'gpu' files
 # The parent gyp/gypi file must define
 #       'skia_src_path'     e.g. skia/trunk/src
 #       'skia_include_path' e.g. skia/trunk/include
 #
 # The skia build defines these in common_variables.gypi
 #
 {
   'variables': {
     'skgpu_sources': [
       '<(skia_include_path)/gpu/GrBackendEffectFactory.h',
-      '<(skia_include_path)/gpu/GrBitmapTextContext.h',
       '<(skia_include_path)/gpu/GrClipData.h',
       '<(skia_include_path)/gpu/GrColor.h',
       '<(skia_include_path)/gpu/GrConfig.h',
       '<(skia_include_path)/gpu/GrContext.h',
       '<(skia_include_path)/gpu/GrContextFactory.h',
       '<(skia_include_path)/gpu/GrCoordTransform.h',
       '<(skia_include_path)/gpu/GrEffect.h',
       '<(skia_include_path)/gpu/GrEffectStage.h',
       '<(skia_include_path)/gpu/GrEffectUnitTest.h',
       '<(skia_include_path)/gpu/GrFontScaler.h',
       '<(skia_include_path)/gpu/GrGlyph.h',
       '<(skia_include_path)/gpu/GrKey.h',
       '<(skia_include_path)/gpu/GrPaint.h',
       '<(skia_include_path)/gpu/GrPathRendererChain.h',
       '<(skia_include_path)/gpu/GrPoint.h',
       '<(skia_include_path)/gpu/GrRect.h',
       '<(skia_include_path)/gpu/GrRenderTarget.h',
       '<(skia_include_path)/gpu/GrResource.h',
       '<(skia_include_path)/gpu/GrSurface.h',
       '<(skia_include_path)/gpu/GrTBackendEffectFactory.h',
-      '<(skia_include_path)/gpu/GrTextContext.h',
       '<(skia_include_path)/gpu/GrTexture.h',
       '<(skia_include_path)/gpu/GrTextureAccess.h',
       '<(skia_include_path)/gpu/GrTypes.h',
       '<(skia_include_path)/gpu/GrUserConfig.h',
 
       '<(skia_include_path)/gpu/gl/GrGLConfig.h',
       '<(skia_include_path)/gpu/gl/GrGLExtensions.h',
       '<(skia_include_path)/gpu/gl/GrGLFunctions.h',
       '<(skia_include_path)/gpu/gl/GrGLInterface.h',
 
       '<(skia_src_path)/gpu/GrAAHairLinePathRenderer.cpp',
       '<(skia_src_path)/gpu/GrAAHairLinePathRenderer.h',
       '<(skia_src_path)/gpu/GrAAConvexPathRenderer.cpp',
       '<(skia_src_path)/gpu/GrAAConvexPathRenderer.h',
       '<(skia_src_path)/gpu/GrAARectRenderer.cpp',
       '<(skia_src_path)/gpu/GrAARectRenderer.h',
       '<(skia_src_path)/gpu/GrAddPathRenderers_default.cpp',
       '<(skia_src_path)/gpu/GrAllocator.h',
       '<(skia_src_path)/gpu/GrAllocPool.h',
       '<(skia_src_path)/gpu/GrAllocPool.cpp',
       '<(skia_src_path)/gpu/GrAtlas.cpp',
       '<(skia_src_path)/gpu/GrAtlas.h',
       '<(skia_src_path)/gpu/GrBinHashKey.h',
       '<(skia_src_path)/gpu/GrBitmapTextContext.cpp',
+      '<(skia_src_path)/gpu/GrBitmapTextContext.h',
       '<(skia_src_path)/gpu/GrBlend.cpp',
       '<(skia_src_path)/gpu/GrBlend.h',
       '<(skia_src_path)/gpu/GrBufferAllocPool.cpp',
       '<(skia_src_path)/gpu/GrBufferAllocPool.h',
       '<(skia_src_path)/gpu/GrCacheID.cpp',
       '<(skia_src_path)/gpu/GrClipData.cpp',
       '<(skia_src_path)/gpu/GrContext.cpp',
       '<(skia_src_path)/gpu/GrDefaultPathRenderer.cpp',
       '<(skia_src_path)/gpu/GrDefaultPathRenderer.h',
       '<(skia_src_path)/gpu/GrDrawState.cpp',
@@ skipping 43 matching lines @@
       '<(skia_src_path)/gpu/GrStencilBuffer.cpp',
       '<(skia_src_path)/gpu/GrStencilBuffer.h',
       '<(skia_src_path)/gpu/GrTBSearch.h',
       '<(skia_src_path)/gpu/GrSWMaskHelper.cpp',
       '<(skia_src_path)/gpu/GrSWMaskHelper.h',
       '<(skia_src_path)/gpu/GrSoftwarePathRenderer.cpp',
       '<(skia_src_path)/gpu/GrSoftwarePathRenderer.h',
       '<(skia_src_path)/gpu/GrSurface.cpp',
       '<(skia_src_path)/gpu/GrTemplates.h',
       '<(skia_src_path)/gpu/GrTextContext.cpp',
+      '<(skia_src_path)/gpu/GrTextContext.h',
       '<(skia_src_path)/gpu/GrTextStrike.cpp',
       '<(skia_src_path)/gpu/GrTextStrike.h',
       '<(skia_src_path)/gpu/GrTextStrike_impl.h',
       '<(skia_src_path)/gpu/GrTexture.cpp',
       '<(skia_src_path)/gpu/GrTextureAccess.cpp',
       '<(skia_src_path)/gpu/GrTHashTable.h',
       '<(skia_src_path)/gpu/GrVertexBuffer.h',
 
       '<(skia_src_path)/gpu/effects/Gr1DKernelEffect.h',
       '<(skia_src_path)/gpu/effects/GrConfigConversionEffect.cpp',
@@ skipping 143 matching lines @@
     ],
     'skgpu_null_gl_sources': [
       '<(skia_src_path)/gpu/gl/GrGLCreateNullInterface.cpp',
 
       # Sk files
       '<(skia_include_path)/gpu/gl/SkNullGLContext.h',
       '<(skia_src_path)/gpu/gl/SkNullGLContext.cpp',
     ],
   },
 }