SkPDF: remove SK_NO_FLATE & dead code in SkPDFStream

SkPDF: remove SK_NO_FLATE & dead code in SkPDFStream

    SkPDFStream copy constructor
    SkPDFStream Substitute mechanism
    SkPDFStream::setData(NULL);
    SkPDFStream SK_NO_FLATE logic

BUG=skia:3585
TBR=bsalomon@google.com,reed@google.com

Committed: https://skia.googlesource.com/skia/+/af9c85dee116fdc5f32029ac6a4fa7882c6b9a63

[hal.canary, 2015-03-30 15:43:34]

The CQ bit was checked by halcanary@google.com

[commit-bot: I haz the power, 2015-03-30 15:43:52]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1041183002/1

[commit-bot: I haz the power, 2015-03-30 15:43:52]

Note for Reviewers:
The CQ is waiting for an approval.
If you believe that the CL is not ready yet, or if you would like to L-G-T-M
with comments then please uncheck the CQ checkbox.

Waiting for LGTM from valid reviewer(s) till 2015-03-30 21:43 UTC

[hal.canary, 2015-03-30 15:44:41]

halcanary@google.com changed reviewers:
+ mtklein@google.com

[hal.canary, 2015-03-30 15:44:41]

ptal

[hal.canary, 2015-03-30 15:53:20]

The CQ bit was unchecked by halcanary@google.com

[hal.canary, 2015-03-30 22:58:15]

On 2015/03/30 15:44:41, Hal Canary wrote:
> ptal

oaky?

[mtklein, 2015-03-30 23:06:03]

lgtm

[hal.canary, 2015-03-31 14:53:16]

The CQ bit was checked by halcanary@google.com

[commit-bot: I haz the power, 2015-03-31 14:53:32]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1041183002/20001

[commit-bot: I haz the power, 2015-03-31 14:53:39]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-03-31 14:53:40]

Presubmit check for 1041183002-20001 failed and returned exit status 1.

Running presubmit commit checks ...

** Presubmit ERRORS **
Since the CL is editing public API, you must have an LGTM from one of:
('reed@chromium.org', 'reed@google.com', 'bsalomon@chromium.org',
'bsalomon@google.com', 'djsollen@chromium.org', 'djsollen@google.com')

[hal.canary, 2015-03-31 15:15:12]

The CQ bit was checked by halcanary@google.com

[commit-bot: I haz the power, 2015-03-31 15:15:28]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1041183002/20001

[commit-bot: I haz the power, 2015-03-31 15:22:06]

Committed patchset #2 (id:20001) as
https://skia.googlesource.com/skia/+/af9c85dee116fdc5f32029ac6a4fa7882c6b9a63