Pack repeated code in tex(Sub)Image2D and texSubImage3D into helper func

third_party/WebKit/Source/modules/webgl/WebGL2RenderingContextBase.h

Index: third_party/WebKit/Source/modules/webgl/WebGL2RenderingContextBase.h
diff --git a/third_party/WebKit/Source/modules/webgl/WebGL2RenderingContextBase.h b/third_party/WebKit/Source/modules/webgl/WebGL2RenderingContextBase.h
index 05f34990b621ef4b688365ad63ef979baacbb049..578b50acbad0df45d7ce2b04a6a060e2c8ef4395 100644
--- a/third_party/WebKit/Source/modules/webgl/WebGL2RenderingContextBase.h
+++ b/third_party/WebKit/Source/modules/webgl/WebGL2RenderingContextBase.h
@@ -235,7 +235,6 @@ protected:
 
     ScriptValue getInt64Parameter(ScriptState*, GLenum);
 
-    void texSubImage3DImpl(GLenum, GLint, GLint, GLint, GLint, GLenum, GLenum, Image*, WebGLImageConversion::ImageHtmlDomSource, bool, bool);
     void samplerParameter(WebGLSampler*, GLenum, GLfloat, GLint, bool);
 
     bool isBufferBoundToTransformFeedback(WebGLBuffer*);
@@ -263,6 +262,7 @@ protected:
     GLint getMaxTextureLevelForTarget(GLenum target) override;
     void renderbufferStorageImpl(GLenum target, GLsizei samples, GLenum internalformat, GLsizei width, GLsizei height, const char* functionName) override;
 
+    WebGLTexture* validateTexImageBinding(const char*, TexImageFunctionName, GLenum) override;
     // Helper function to check texture 3D target and texture bound to the target.
     // Generate GL errors and return 0 if target is invalid or texture bound is
     // null.  Otherwise, return the texture bound to the target.