Revert of Be explicit about forcing TouchSelectionController updates (patchset #2 id:20001 of https://codereview.chromium.org/1127383007/)

Reason for revert:
This has caused failures on the memory bots. e.g.:http://build.chromium.org/p/chromium.memory.fyi/builders/Linux%20MSan%20Tests/builds/6179

Sample test output:
[ RUN      ] TouchSelectionControllerTest.AllowShowingFromCurrentSelection
==6485== WARNING: MemorySanitizer: use-of-uninitialized-value
    #0 0x7f5bc93bb605 in ui::TouchSelectionController::OnSelectionBoundsChanged(ui::SelectionBound const&, ui::SelectionBound const&) ui/touch_selection/touch_selection_controller.cc:71:27
    #1 0x7f5bc922803a in ui::TouchSelectionControllerTest::ChangeSelection(gfx::RectF const&, bool, gfx::RectF const&, bool) ui/touch_selection/touch_selection_controller_unittest.cc:147:5
    #2 0x7f5bc9278c8d in ui::TouchSelectionControllerTest_AllowShowingFromCurrentSelection_Test::TestBody() ui/touch_selection/touch_selection_controller_unittest.cc:946:3
    #3 0x7f5bc93631dc in HandleExceptionsInMethodIfSupported\u003Ctesting::Test, void> testing/gtest/src/gtest.cc:2420:12
    #4 0x7f5bc93631dc in testing::Test::Run() testing/gtest/src/gtest.cc:2436:0
    #5 0x7f5bc9365a4c in testing::TestInfo::Run() testing/gtest/src/gtest.cc:2612:5
    #6 0x7f5bc93673f6 in testing::TestCase::Run() testing/gtest/src/gtest.cc:2730:5
    #7 0x7f5bc9384d03 in testing::internal::UnitTestImpl::RunAllTests() testing/gtest/src/gtest.cc:4602:11
    #8 0x7f5bc9383ce2 in HandleExceptionsInMethodIfSupported\u003Ctesting::internal::UnitTestImpl, bool> testing/gtest/src/gtest.cc:2420:12
    #9 0x7f5bc9383ce2 in testing::UnitTest::Run() testing/gtest/src/gtest.cc:4220:0
    #10 0x7f5bc93078a3 in RUN_ALL_TESTS testing/gtest/include/gtest/gtest.h:2326:10
    #11 0x7f5bc93078a3 in base::TestSuite::Run() base/test/test_suite.cc:228:0
    #12 0x7f5bc92f7b2d in (anonymous namespace)::RunTestSuite(int, char**) base/test/run_all_unittests.cc:25:10
    #13 0x7f5bc92f85ee in Run base/callback.h:396:12
    #14 0x7f5bc92f85ee in base::(anonymous namespace)::LaunchUnitTestsInternal(base::Callback\u003Cint ()> const&, int, bool, base::Callback\u003Cvoid ()> const&) base/test/launcher/unit_test_launcher.cc:184:0
    #15 0x7f5bc92f7f5b in base::LaunchUnitTests(int, char**, base::Callback\u003Cint ()> const&) base/test/launcher/unit_test_launcher.cc:423:10
    #16 0x7f5bc92f792d in main base/test/run_all_unittests.cc:37:10
    #17 0x7f5bc206a76c in __libc_start_main /build/buildd/eglibc-2.15/csu/libc-start.c:226:0
    #18 0x7f5bc9188f38 in _start ??:0:0

  Uninitialized value was created by a heap allocation
    #0 0x7f5bc91da0e2 in operator new(unsigned long) ??:0:0
    #1 0x7f5bc927c95c in ui::TouchSelectionControllerTest::SetUp() ui/touch_selection/touch_selection_controller_unittest.cc:65:23
    #2 0x7f5bc9362f57 in HandleExceptionsInMethodIfSupported\u003Ctesting::Test, void> testing/gtest/src/gtest.cc:2420:12
    #3 0x7f5bc9362f57 in testing::Test::Run() testing/gtest/src/gtest.cc:2432:0
    #4 0x7f5bc9365a4c in testing::TestInfo::Run() testing/gtest/src/gtest.cc:2612:5
    #5 0x7f5bc93673f6 in testing::TestCase::Run() testing/gtest/src/gtest.cc:2730:5
    #6 0x7f5bc9384d03 in testing::internal::UnitTestImpl::RunAllTests() testing/gtest/src/gtest.cc:4602:11
    #7 0x7f5bc9383ce2 in HandleExceptionsInMethodIfSupported\u003Ctesting::internal::UnitTestImpl, bool> testing/gtest/src/gtest.cc:2420:12
    #8 0x7f5bc9383ce2 in testing::UnitTest::Run() testing/gtest/src/gtest.cc:4220:0
    #9 0x7f5bc93078a3 in RUN_ALL_TESTS testing/gtest/include/gtest/gtest.h:2326:10
    #10 0x7f5bc93078a3 in base::TestSuite::Run() base/test/test_suite.cc:228:0
    #11 0x7f5bc92f7b2d in (anonymous namespace)::RunTestSuite(int, char**) base/test/run_all_unittests.cc:25:10
    #12 0x7f5bc92f85ee in Run base/callback.h:396:12
    #13 0x7f5bc92f85ee in base::(anonymous namespace)::LaunchUnitTestsInternal(base::Callback\u003Cint ()> const&, int, bool, base::Callback\u003Cvoid ()> const&) base/test/launcher/unit_test_launcher.cc:184:0
    #14 0x7f5bc92f7f5b in base::LaunchUnitTests(int, char**, base::Callback\u003Cint ()> const&) base/test/launcher/unit_test_launcher.cc:423:10
    #15 0x7f5bc92f792d in main base/test/run_all_unittests.cc:37:10
    #16 0x7f5bc206a76c in __libc_start_main /build/buildd/eglibc-2.15/csu/libc-start.c:226:0

SUMMARY: MemorySanitizer: use-of-uninitialized-value (/mnt/data/b/build/slave/Linux_MSan_Tests/build/src/out/Release/ui_touch_selection_unittests+0x285605)
Exiting

Original issue's description:
> Be explicit about forcing TouchSelectionController updates
>
> Previously, cached values in the TouchSelectionController would be reset
> to force future selection updates. However, these cached values can
> actually be used outside of selection update calls, e.g., when force
> showing the selection from the current cached values. Instead of
> resetting the cached values, simply set a dirty bit that forces an
> update, avoiding issues when dealing with the reset values.
>
> BUG=393025
>
> Committed: https://crrev.com/fdcf817da49ee92fe191981f7525503444f75f83
> Cr-Commit-Position: refs/heads/master@{#329325}

TBR=mohsen@chromium.org,jdduke@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=393025

Review URL: https://codereview.chromium.org/1139533006

Cr-Commit-Position: refs/heads/master@{#329352}

3 files changed, 15 insertions, 19 deletions

diff --git a/ui/touch_selection/touch_selection_controller.cc b/ui/touch_selection/touch_selection_controller.cc
index 47ecf5a..1c8ceae 100644
--- a/ui/touch_selection/touch_selection_controller.cc
+++ b/ui/touch_selection/touch_selection_controller.cc
@@ -68,14 +68,13 @@ TouchSelectionController::~TouchSelectionController() {
 void TouchSelectionController::OnSelectionBoundsChanged(
     const SelectionBound& start,
     const SelectionBound& end) {
-  if (!force_next_update_ && start == start_ && end_ == end)
+  if (start == start_ && end_ == end)
     return;
 
   start_ = start;
   end_ = end;
   start_orientation_ = ToTouchHandleOrientation(start_.type());
   end_orientation_ = ToTouchHandleOrientation(end_.type());
-  force_next_update_ = false;
 
   if (!activate_selection_automatically_ &&
       !activate_insertion_automatically_) {
@@ -156,7 +155,7 @@ void TouchSelectionController::OnLongPressEvent() {
   response_pending_input_event_ = LONG_PRESS;
   ShowSelectionHandlesAutomatically();
   ShowInsertionHandleAutomatically();
-  ForceNextUpdateIfInactive();
+  ResetCachedValuesIfInactive();
 }
 
 void TouchSelectionController::AllowShowingFromCurrentSelection() {
@@ -180,7 +179,7 @@ void TouchSelectionController::OnTapEvent() {
   ShowInsertionHandleAutomatically();
   if (selection_empty_ && !show_on_tap_for_empty_editable_)
     DeactivateInsertion();
-  ForceNextUpdateIfInactive();
+  ResetCachedValuesIfInactive();
 }
 
 void TouchSelectionController::HideAndDisallowShowingAutomatically() {
@@ -209,7 +208,7 @@ void TouchSelectionController::OnSelectionEditable(bool editable) {
   if (selection_editable_ == editable)
     return;
   selection_editable_ = editable;
-  ForceNextUpdateIfInactive();
+  ResetCachedValuesIfInactive();
   if (!selection_editable_)
     DeactivateInsertion();
 }
@@ -218,7 +217,7 @@ void TouchSelectionController::OnSelectionEmpty(bool empty) {
   if (selection_empty_ == empty)
     return;
   selection_empty_ = empty;
-  ForceNextUpdateIfInactive();
+  ResetCachedValuesIfInactive();
 }
 
 bool TouchSelectionController::Animate(base::TimeTicks frame_time) {
@@ -341,14 +340,14 @@ void TouchSelectionController::ShowInsertionHandleAutomatically() {
   if (activate_insertion_automatically_)
     return;
   activate_insertion_automatically_ = true;
-  ForceNextUpdateIfInactive();
+  ResetCachedValuesIfInactive();
 }
 
 void TouchSelectionController::ShowSelectionHandlesAutomatically() {
   if (activate_selection_automatically_)
     return;
   activate_selection_automatically_ = true;
-  ForceNextUpdateIfInactive();
+  ResetCachedValuesIfInactive();
 }
 
 void TouchSelectionController::OnInsertionChanged() {
@@ -464,9 +463,13 @@ void TouchSelectionController::DeactivateSelection() {
   client_->OnSelectionEvent(SELECTION_CLEARED);
 }
 
-void TouchSelectionController::ForceNextUpdateIfInactive() {
-  if (active_status_ == INACTIVE)
-    force_next_update_ = true;
+void TouchSelectionController::ResetCachedValuesIfInactive() {
+  if (active_status_ != INACTIVE)
+    return;
+  start_ = SelectionBound();
+  end_ = SelectionBound();
+  start_orientation_ = TouchHandleOrientation::UNDEFINED;
+  end_orientation_ = TouchHandleOrientation::UNDEFINED;
 }
 
 gfx::Vector2dF TouchSelectionController::GetStartLineOffset() const {
diff --git a/ui/touch_selection/touch_selection_controller.h b/ui/touch_selection/touch_selection_controller.h
index 4f6a578..f1a434d 100644
--- a/ui/touch_selection/touch_selection_controller.h
+++ b/ui/touch_selection/touch_selection_controller.h
@@ -132,7 +132,7 @@ class UI_TOUCH_SELECTION_EXPORT TouchSelectionController
   void DeactivateInsertion();
   void ActivateSelection();
   void DeactivateSelection();
-  void ForceNextUpdateIfInactive();
+  void ResetCachedValuesIfInactive();
 
   gfx::Vector2dF GetStartLineOffset() const;
   gfx::Vector2dF GetEndLineOffset() const;
@@ -146,10 +146,6 @@ class UI_TOUCH_SELECTION_EXPORT TouchSelectionController
   const base::TimeDelta tap_timeout_;
   const float tap_slop_;
 
-  // Whether to force an update on the next selection event even if the
-  // cached selection matches the new selection.
-  bool force_next_update_;
-
   // Controls whether an insertion handle is shown on a tap for an empty
   // editable text.
   bool show_on_tap_for_empty_editable_;
diff --git a/ui/touch_selection/touch_selection_controller_unittest.cc b/ui/touch_selection/touch_selection_controller_unittest.cc
index 46c2f4f..6a22b0e 100644
--- a/ui/touch_selection/touch_selection_controller_unittest.cc
+++ b/ui/touch_selection/touch_selection_controller_unittest.cc
@@ -946,9 +946,6 @@ TEST_F(TouchSelectionControllerTest, AllowShowingFromCurrentSelection) {
   ChangeSelection(start_rect, visible, end_rect, visible);
   EXPECT_EQ(gfx::PointF(), GetLastEventStart());
 
-  // A longpress should have no immediate effect.
-  controller().OnLongPressEvent();
-
   // Now explicitly allow showing from the previously supplied bounds.
   controller().AllowShowingFromCurrentSelection();
   EXPECT_THAT(GetAndResetEvents(), ElementsAre(SELECTION_SHOWN));