Add flag for single click autofill.

This currently defaults to off and if enabled will show suggestions when the mouse is first clicked in an edit box.

Converts ShowSuggestions function call which took 6 bool parameters to take a struct for clarity and future enhancement.

Review URL: https://codereview.chromium.org/753393004

Cr-Commit-Position: refs/heads/master@{#305889}
diff --git a/chrome/browser/about_flags.cc b/chrome/browser/about_flags.cc
index 4d440a0..f866bd9 100644
--- a/chrome/browser/about_flags.cc
+++ b/chrome/browser/about_flags.cc
@@ -1670,6 +1670,15 @@
         autofill::switches::kRespectAutocompleteOffForAutofill)
   },
   {
+    "enable-single-click-autofill",
+    IDS_FLAGS_ENABLE_SINGLE_CLICK_AUTOFILL_NAME,
+    IDS_FLAGS_ENABLE_SINGLE_CLICK_AUTOFILL_DESCRIPTION,
+    kOsCrOS | kOsMac | kOsWin | kOsLinux,
+    ENABLE_DISABLE_VALUE_TYPE(
+        autofill::switches::kEnableSingleClickAutofill,
+        autofill::switches::kDisableSingleClickAutofill)
+  },
+  {
     "enable-permissions-bubbles",
     IDS_FLAGS_ENABLE_PERMISSIONS_BUBBLES_NAME,
     IDS_FLAGS_ENABLE_PERMISSIONS_BUBBLES_DESCRIPTION,