JsonWriter requires that its clients pass it only a single top-level object.
The existing implementation tries to make code cleaner by having mJsonWriter
never be null, and instead use a global static "NULL_JSON_WRITER" that just
discards data.  But because JsonWriter complains if more than one top-level
object is passed, making this a global object does not work.  This change
instead copes with mJsonWriter being null.

Change-Id: Ia37ccfc8646e91f11a64713dd92d2846eb86ac54

JsonWriter requires that data be written to it, else close() will throw
an exception.

Change-Id: I596c5363e063cc75bcda55e0a506eefb3f17bd67

bug: 8393568
Change-Id: Ie5edf44a3627aca9416145aff56bf05bbf2a05f3

Previously used a monotonically increasing int.  Now uses uuid and nanoseconds.

squashed in:
    [FileEncap11] Read preference from ResearchSettings
    Change-Id: Ic779e0a69db6b16e92c6f4b63dbe7b7add566ab6

    [FileEncap12] Simplify directory cleanup invocation
    Change-Id: I688047409c0343d32b11447fb625dfb726c731ec

    [FileEncap14] Change log filename syntax
    Change-Id: I9243b20b2eb392f81ab8c5c3d19315211240e0bc

Change-Id: I5c9d70e0cb7b0965158e17dd71dfab796bd9a440

Change-Id: I721afbf426099753aa876a55323eb806b08c24d6

Change-Id: I4daec20b7b47b0d71c5aab6e17cd660015e19e71

Change-Id: If2107e38575b009a4c372194ecd827e27bdbb2b4

Change-Id: Ia8e0bd72b0dc09bfc256ec5d1996637554376b5f

Change-Id: If15f250feb81c2ad55ce1bc7dc3dafa57de87aef

Change-Id: I4e97fa28dd0bb1101edc0db03f024432fee6f6fe

Change-Id: Id9a72045afa3558b20b9d63c8720fb7443d34fd9

multi-project commit with I1212da392ecda0ad78962da68941870b5a651eee

Change-Id: Ie74af59d4e45bf954723fee9dcf350a36468c381

Previously, words were pushed out of a LogBuffer one at a time.  The receiving code had to keep
state to know whether a n-gram was safe to log.  This patch looks at the entire n-gram and makes a
single decision based on it alone.

mult-project commit with I3c40d7e02c77943d2668094ddb1d03efb942c74f

Change-Id: Id7d90bbd551b1a2f4e0e35f38852652f68f273f8

Change-Id: Ic56167f952a7f4449da366e1e81610e72c966086

multi-project commit with If6b9f8990d7cdbf570740a81096513698d0e0f4c

Change-Id: I124aed24be0beb4c472869594184ecf003c2fed4

Change-Id: Ia3fca4881370ffcdd5f2b14d2d1094c51f4330ae

Move specifics of Log output format from ResearchLog to LogUnit

Change-Id: I9d0253c50bb8175ab141bd87dd9a09f39f316b10

The IS_EXPERIMENTAL_DEBUG flag gives a single place to turn off all debugging flags that might be
set and to also enforce privacy controls.  Currently only used in the research package.

multi-project commit with I9275a7c8e40bf56106447a02d3056655329074b3

Change-Id: If769fe3a633f33963ca49e8ddf01ab24a30b6fd2

multi-space logging should look like single-space logging, missing a few minor log statements
(SuggestionUpdates, SetComposingText)

multi-project commit with I2af842348c2f2b8f7271ac5b63def245e83df24d

Change-Id: Icd3187c0d0377255f82787afffea657c14345803

Log statements are now recorded with a timestamp.  This is important for filtering out statements
not part of words that are sampled when spaces are inserted automatically.

multi-project commit with Change-Id: I68221a2528045d25632aef4bb716f92a4f4a56a4

Change-Id: I46ac9b3b1dcbb08425160d0109028cb64445139c

This reverts commit bdbe279c

Other half of this change couldn't be committed because of a inter-project directory migration.  Reverting until things settle down.

Change-Id: I3862fc8485dfca6d507f620e905cfa583aa0e39a

Log statements are now recorded with a timestamp.  This is important for filtering out statements
not part of words that are sampled when spaces are inserted automatically.

multi-project commit with Change-Id: I68221a2528045d25632aef4bb716f92a4f4a56a4

Change-Id: I9f49c36391e1e1773b6d4876d7387c893024f87b

Change-Id: I0abb4a1ad67666162ab6703ffdb33c5e0675be93

Bug: 6188932
Change-Id: I31c0f380b334d9117990f2d92de8d385e4a52c7c

This change also removes per-Key verticalGap and horizontalGap.

Change-Id: Id4d2129022fbbfbf5d740b8d1257032c945bb775

- Captures complete motion data for all words in an n-gram.
- Also filters n-grams properly; if any word in the n-gram is not
  in the dictionary, it is not included.
- Simplify ResearchLog to not require explicit state
- Added LogBuffer class MainLogBuffer class to allow n-gram-level decisions
  about privacy.
- Moved LogUnit out from ResearchLogger

multi-project change with Ic70ccb6c2e11eb02d887821434b44daa3eb7a3e2

Bug: 6188932
Change-Id: I731d6cff6539e997874f723b68bdb0d9b651b937

This reverts commit 221e756f

Change-Id: Iefc4e4e27ddc925d4a4634627b0467bd4ee2a66e

DO NOT MERGE

- Captures complete motion data for all words in an n-gram.
- Also filters n-grams properly; if any word in the n-gram is not
  in the dictionary, it is not included.
- Simplify ResearchLog to not require explicit state
- Added LogBuffer class MainLogBuffer class to allow n-gram-level decisions
  about privacy.
- Moved LogUnit out from ResearchLogger

multi-project change with Ie2bc79fd7fe6b951b24771e94b8d4ca21989af65

Bug: 6188932
Change-Id: I568c90d4af07e7c759c1e7fc64b716bd8c7b4ae5

Change-Id: Ia710721774a85ee8ac20ba1f1dc117768e281190

- Captures complete motion data for all words in an n-gram.
- Also filters n-grams properly; if any word in the n-gram is not
  in the dictionary, it is not included.
- Simplify ResearchLog to not require explicit state
- Added LogBuffer class MainLogBuffer class to allow n-gram-level decisions
  about privacy.
- Moved LogUnit out from ResearchLogger

multi-project change with Id997fb6572daa3ff55591afa1676953bb204f33a

Because of a strange Gerrit interaction, earlier patchsets were recorded
as the following separate changes (to soon be abandoned):

- I59d86ae28123890ddb7aabc7dc9a73a75eecbca4
- I9cc95266fa4500d019e09ec53ec00e5dea7ffd38
- Ie6f23a2035e160f231406df1388a43725380df1d
- Id87909e96fa7fa91174c86395a964404f3490fe1
- I57c5cbde0425c42538d589fa4d1802b3e5688f7c
- Ic1f9d7727e416da1b6c4f1a45b53750cd4088dcf
- I20a72ccc4ba1bc08ed3ee39bff71d2adb376588c
- I417f6f364144b90085f5fef4bd2de1a40b5dfa79

Bug: 6188932
Change-Id: I771e57e3b8c0eb6721c2022e775cb0b528bdff93

- new package: com.android.inputmethod.research

multi-project commit with Ic0a5744f3160d13218addd589890623c0d120ffc

Bug: 6188932

Change-Id: Icf8d4a40a5725401799be6e209a640d99a5f34c4

Bug: 6188932
Change-Id: I692e427ba2e6da7bb15f48208304c4a034392a22

- separate ResearchLog from ResearchLogger
- fix abort menu to explicitly indicate re-enabling of logging
- auto flush entries every 5s
- conform to new suggestedWords class

multi-project change with I9fe1f8fe59d5891daa4ca84af157f36fb1bb17dc

Bug: 6188932

Change-Id: I7e99390f934481c6ed9cea2b259944583edda5bb