Adding a chrome flag to control the touch selection granularity strategy used by Blink.

chrome/browser/about_flags.cc

Index: chrome/browser/about_flags.cc
diff --git a/chrome/browser/about_flags.cc b/chrome/browser/about_flags.cc
index 7f41b7f2bcae79c6519c8e376d453503e43fae94..c0d616bf85d59060c66bae6f07879f4efa893877 100644
--- a/chrome/browser/about_flags.cc
+++ b/chrome/browser/about_flags.cc
@@ -173,6 +173,13 @@ const Experiment::Choice kOverscrollHistoryNavigationChoices[] = {
 };
 #endif
 
+const Experiment::Choice kTouchTextSelectionStrategyChoices[] = {
+  { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT, "", "" },
+  { IDS_TOUCH_SELECTION_STRATEGY_DIRECTION,
+    switches::kTouchTextSelectionStrategy,

[jdduke (slow), 2015/04/17 15:20:29]

I'd be OK if we just called this |kEnableSmartTextSelection| or something like
that. Not sure we even need it in about:flags, but if we do add it here we might
restrict the OS to where it will be available (Android).

[mfomitchev, 2015/04/17 16:22:39]

You are a bit ahead of me. Check out
https://codereview.chromium.org/1096773002/.

+    "1" }
+};
+
 #if !defined(DISABLE_NACL)
 const Experiment::Choice kNaClDebugMaskChoices[] = {
   // Secure shell can be used on ChromeOS for forwarding the TCP port opened by
@@ -1103,6 +1110,13 @@ const Experiment kExperiments[] = {
                               switches::kDisableTouchEditing)
   },
   {
+      "touch-selection-strategy",
+      IDS_FLAGS_TOUCH_SELECTION_STRATEGY_NAME,
+      IDS_FLAGS_TOUCH_SELECTION_STRATEGY_DESCRIPTION,
+      kOsAll,
+      MULTI_VALUE_TYPE(kTouchTextSelectionStrategyChoices)
+  },
+  {
     "enable-stale-while-revalidate",
     IDS_FLAGS_ENABLE_STALE_WHILE_REVALIDATE_NAME,
     IDS_FLAGS_ENABLE_STALE_WHILE_REVALIDATE_DESCRIPTION,