Cleanup and prepare for replaying

Change-Id: Ie09e912c6e9c0d7375168c575ccf1cfd9375dd31

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

- broaden OUTPUT_WHOLE_BUFFER to log not just the buffer at the end, but everything along the
  way.  This should only be set when the user is aware that logging is on, e.g. in a user test.

Change-Id: I8f9874697524e533586da40d0a3e452f6a04d3e4

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

Change-Id: I03729506984f259dee63f3a66fd91963e3403d16

- 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

- 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