[SPARK-13098][SQL] remove GenericInternalRowWithSchema

[cloud-fan]

This class is only used for serialization of Python DataFrame. However, we don't require internal row there, so GenericRowWithSchema can also do the job.

[SparkQA]

Test build #50418 has finished for PR 10992 at commit 57707df.

• This patch fails Spark unit tests.
• This patch merges cleanly.
• This patch adds no public classes.

[cloud-fan]

retest this please

[SparkQA]

Test build #50423 has finished for PR 10992 at commit 57707df.

• This patch fails Spark unit tests.
• This patch merges cleanly.
• This patch adds no public classes.

[cloud-fan]

retest this please

[SparkQA]

Test build #50428 has finished for PR 10992 at commit 57707df.

• This patch fails Spark unit tests.
• This patch merges cleanly.
• This patch adds no public classes.

[cloud-fan]

retest this please.

[SparkQA]

Test build #50434 has finished for PR 10992 at commit 57707df.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds no public classes.

[cloud-fan]

cc @davies

[davies]

The difference between Row and InternalRow is that the objects inside InternalRow should be internal types. For this case, we pickle the objects in internal types, so it should be InternalRow (it's more clear even with some duplicated codes).

[cloud-fan]

in toJava, we convert internal types to exteral ones(e.g. UTF8String -> String, ArrayData -> ArrayList), the InternalRow is the only exception, we convert it to GenericInternalRowWithSchema! I think using GenericRowWithSchema is more clear for it.

[davies]

@cloud-fan I see, that make sense. LGTM, merging this into master, thanks!

[davies]

@cloud-fan btw, it's not external type either, for example, it's Int for DateType, not java.sql.Date.