After HideCaret() is called via keyboard event,
OnScrollPositionChanged() still fire another CaretStateChanged event
even if the caret is hidden. We follow OnReflow() to update carets only
when carets are logically visible.
A test case:
1. Type a string on the rocketbar until the text is long enough to scroll.
2. Copy arbitrary string.
3. Tap on rocketbar to show caret, and move it to the end (within 15
seconds timeout)
4. Type a character.
The text selection dialog should not show.
We should dispatch CaretStateChanged event in OnReflow() in cursor mode
when the first caret's appearance is NormalNotShown. Otherwise the text
selection dialog won't update its position.
I now think that mLastUpdateCaretMode is an implementation detail. Test
it will make test and implementation coupled.
It's better to call EXPECT_EQ directly in test functions so that the
line number in test result will be accurate when things go wrong.
Add basic gtest to ensure AccessibleCaret and AccessibleCaretManager are
both testable. More tests to come.
Allow -Winconsistent-missing-override warning in gtest since MOCK_METHOD
does not have 'override' keyword. See bug 1169974.
