Hpack fuzzing tweaks to address CHECK failures on ClusterFuzz

Hpack fuzzing tweaks to address CHECK failures on ClusterFuzz

* Be tolerant of truncated files. These happen in practice if the fuzzer
runs out of disk space.

* Clear the decoder's input buffer if decoding fails.

* Relax third-stage decoder checks, as there are valid cases where the
second-stage encoder produces an output which the decoder will refuse.

BUG=353237
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=269951

[Ryan Hamilton, 2014-05-12 21:05:49]

lgtm

https://codereview.chromium.org/284643002/diff/1/net/spdy/fuzzing/hpack_fuzz_...
File net/spdy/fuzzing/hpack_fuzz_util.cc (right):

https://codereview.chromium.org/284643002/diff/1/net/spdy/fuzzing/hpack_fuzz_...
net/spdy/fuzzing/hpack_fuzz_util.cc:170: if
(!context->third_stage->HandleControlFrameHeadersComplete(1)) {
Up to you, but you could write this as:

return context->third_stage->HandleControlFrameHeadersData(
          1, second_stage_out.data(), second_stage_out.length()) &&
       context->third_stage->HandleControlFrameHeadersComplete(1);

Perhaps this is not actually any better :>

[Johnny, 2014-05-12 22:28:09]

The CQ bit was checked by jgraettinger@chromium.org

[commit-bot: I haz the power, 2014-05-12 22:28:39]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/jgraettinger@chromium.org/284643002/1

[commit-bot: I haz the power, 2014-05-13 01:10:47]

Change committed as 269951