Permissions: Show the reason for permission decisions made on the user's behalf.

chrome/browser/ui/views/page_info/permission_selector_row.cc

Index: chrome/browser/ui/views/page_info/permission_selector_row.cc
diff --git a/chrome/browser/ui/views/page_info/permission_selector_row.cc b/chrome/browser/ui/views/page_info/permission_selector_row.cc
index ac79ebc88ffa57a1b3482b3f99ebb98c1b888e19..3c665b485594c51e2f3c5f56d6d3262e0133de84 100644
--- a/chrome/browser/ui/views/page_info/permission_selector_row.cc
+++ b/chrome/browser/ui/views/page_info/permission_selector_row.cc
@@ -266,6 +266,21 @@ PermissionSelectorRow::PermissionSelectorRow(
     InitializeComboboxView(layout, permission);
   else
     InitializeMenuButtonView(layout, permission);
+
+  // Show the permission decision reason, if it was not the user.
+  base::string16 reason =
+      PageInfoUI::PermissionDecisionReasonToUIString(profile, permission, url);
+  if (!reason.empty()) {
+    layout->StartRow(1, 1);
+    layout->SkipColumns(1);
+    views::Label* permission_decision_reason = new views::Label(reason);
+    permission_decision_reason->SetEnabledColor(SK_ColorGRAY);

[lgarron, 2017/03/29 05:49:26]

Note that "High Contrast Black" mode on Windows has a black background for Page
Info. This shade of gray actually has pretty good contrast [1]; did the specs
explicitly cover this case, though?

[1] http://leaverou.github.io/contrast-ratio/#black-on-%23888888

[Patti Lor, 2017/03/30 03:27:29]

No, they don't - there actually aren't any for non-MD page info. Thanks for
bringing this up and checking the contrast though.

+    // Long labels should span the remaining width of the row.
+    views::ColumnSet* column_set = layout->GetColumnSet(1);
+    DCHECK(!!column_set);

[lgarron, 2017/03/29 05:49:26]

More of a question for me to learn: Is this pattern common?
Other Page Info DCHECKs just pass the pointer directly, and I can't find
documentation about the recommended approach.

[Patti Lor, 2017/03/30 03:27:29]

Good point - I've seen it before but I don't think it was common. Codesearch
says there are only 15 instances places where "DCHECK(!!" is found, so I'll
change it.

+    layout->AddView(permission_decision_reason, column_set->num_columns() - 2,
+                    1, views::GridLayout::LEADING, views::GridLayout::CENTER);
+  }
 }
 
 void PermissionSelectorRow::AddObserver(