Initial work to get ETC1 data up to the GPU

src/gpu/gl/GrGpuGL.h

Index: src/gpu/gl/GrGpuGL.h
diff --git a/src/gpu/gl/GrGpuGL.h b/src/gpu/gl/GrGpuGL.h
index f548af5f6aabd4cecd853f1c6af289287e478b46..f2a358333869faf499cf1bc6077aed1920599bce 100644
--- a/src/gpu/gl/GrGpuGL.h
+++ b/src/gpu/gl/GrGpuGL.h
@@ -124,6 +124,9 @@ private:
     virtual GrTexture* onCreateTexture(const GrTextureDesc& desc,
                                        const void* srcData,
                                        size_t rowBytes) SK_OVERRIDE;
+    virtual GrTexture* onCreateCompressedTexture(const GrTextureDesc& desc,
+                                                 const void* srcData,
+                                                 GrCompressedFormat format) SK_OVERRIDE;
     virtual GrVertexBuffer* onCreateVertexBuffer(size_t size, bool dynamic) SK_OVERRIDE;
     virtual GrIndexBuffer* onCreateIndexBuffer(size_t size, bool dynamic) SK_OVERRIDE;
     virtual GrPath* onCreatePath(const SkPath&, const SkStrokeRec&) SK_OVERRIDE;
@@ -265,6 +268,12 @@ private:
                        const void* data,
                        size_t rowBytes);
 
+    // helper for onCreateCompressedTexture
+    bool compressedFormatToGLFormats(GrCompressedFormat fmt, GrGLenum* internalFormat);
+    bool uploadCompressedTexData(const GrGLTexture::Desc& desc,
+                                 GrCompressedFormat fmt,
+                                 const void* data);
+
     bool createRenderTargetObjects(int width, int height,
                                    GrGLuint texID,
                                    GrGLRenderTarget::Desc* desc);