add diff recording and output code

add diff recording and output code

R=bsalomon@google.com

Committed: https://code.google.com/p/skia/source/detail?r=9875

[bsalomon, 2013-07-02 13:37:15]

most looks good, some nits

https://codereview.chromium.org/18348011/diff/1/experimental/skpdiff/SkDiffCo...
File experimental/skpdiff/SkDiffContext.cpp (right):

https://codereview.chromium.org/18348011/diff/1/experimental/skpdiff/SkDiffCo...
experimental/skpdiff/SkDiffContext.cpp:1: #include "SkBitmap.h"
Need copyright

https://codereview.chromium.org/18348011/diff/1/experimental/skpdiff/SkDiffCo...
experimental/skpdiff/SkDiffContext.cpp:10: SkDiffContext::SkDiffContext()
style nit: { goes on previous line, here and below

https://codereview.chromium.org/18348011/diff/1/experimental/skpdiff/SkDiffCo...
experimental/skpdiff/SkDiffContext.cpp:21: while (currentRecord != NULL) {
we usually write NULL != currentRecord and NULL == currentRecord.  The idea is
that if one were to accidentally type (or edit this) to be NULL = currentRecord,
it wouldn't compile

https://codereview.chromium.org/18348011/diff/1/experimental/skpdiff/SkDiffCo...
experimental/skpdiff/SkDiffContext.cpp:67: for (unsigned differIndex = 0;
differIndex < fDifferCount; differIndex++) {
see above about fDifferCount

https://codereview.chromium.org/18348011/diff/1/experimental/skpdiff/SkDiffCo...
experimental/skpdiff/SkDiffContext.cpp:148: stream.writeText("    \"records\":
[\n");
Maybe the format of the json should be documented somewhere? Perhaps in the
header for this class above the class decl.

https://codereview.chromium.org/18348011/diff/1/experimental/skpdiff/SkDiffCo...
File experimental/skpdiff/SkDiffContext.h (right):

https://codereview.chromium.org/18348011/diff/1/experimental/skpdiff/SkDiffCo...
experimental/skpdiff/SkDiffContext.h:81: size_t fDifferCount;
Does this really need to be 64 bits on a 64 bit machine?

Google/Skia convention is to use plain old "int" for counts (unless they are
byte counts).

[bsalomon, 2013-07-02 19:28:37]

https://codereview.chromium.org/18348011/diff/6001/experimental/skpdiff/SkDif...
File experimental/skpdiff/SkDiffContext.cpp (right):

https://codereview.chromium.org/18348011/diff/6001/experimental/skpdiff/SkDif...
experimental/skpdiff/SkDiffContext.cpp:24: {
up

https://codereview.chromium.org/18348011/diff/6001/experimental/skpdiff/SkDif...
File experimental/skpdiff/SkDiffContext.h (right):

https://codereview.chromium.org/18348011/diff/6001/experimental/skpdiff/SkDif...
experimental/skpdiff/SkDiffContext.h:112: unsigned fDifferCount;
int

[bsalomon, 2013-07-02 19:47:49]

lgtm (other than warning noted below).

https://codereview.chromium.org/18348011/diff/14001/experimental/skpdiff/SkDi...
File experimental/skpdiff/SkDiffContext.cpp (right):

https://codereview.chromium.org/18348011/diff/14001/experimental/skpdiff/SkDi...
experimental/skpdiff/SkDiffContext.cpp:72: for (unsigned differIndex = 0;
differIndex < fDifferCount; differIndex++) {
You'll get a signed/unsigned comparison warning-as-error here.

[Zach Reizner, 2013-07-02 19:55:37]

Committed patchset #4 manually as r9875 (presubmit successful).