Add textfield internal padding from FocusableBorder.

ui/views/controls/textfield/textfield.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/views/controls/textfield/textfield.h"
 
 #include <string>
 
 #include "base/debug/trace_event.h"
 #include "ui/accessibility/ax_view_state.h"
@@ skipping 220 matching lines @@
       return kNoCommand;
   }
   return kNoCommand;
 }
 #endif
 
 }  // namespace
 
 // static
 const char Textfield::kViewClassName[] = "Textfield";
+const int Textfield::kTextPadding = 3;
 
 // static
 size_t Textfield::GetCaretBlinkMs() {
   static const size_t default_value = 500;
 #if defined(OS_WIN)
   static const size_t system_value = ::GetCaretBlinkTime();
   if (system_value != 0)
     return (system_value == INFINITE) ? 0 : system_value;
 #endif
   return default_value;
@@ skipping 297 matching lines @@
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // Textfield, View overrides:
 
 int Textfield::GetBaseline() const {
   return GetInsets().top() + GetRenderText()->GetBaseline();
 }
 
 gfx::Size Textfield::GetPreferredSize() const {
-  const gfx::Insets& insets = GetInsets();
+  gfx::Insets insets = GetInsets();
+  insets += gfx::Insets(kTextPadding, kTextPadding, kTextPadding, kTextPadding);
   return gfx::Size(GetFontList().GetExpectedTextWidth(default_width_in_chars_) +
                    insets.width(), GetFontList().GetHeight() + insets.height());
 }
 
 const char* Textfield::GetClassName() const {
   return kViewClassName;
 }
 
 gfx::NativeCursor Textfield::GetCursor(const ui::MouseEvent& event) {
   bool in_selection = GetRenderText()->IsPointInSelection(event.location());
@@ skipping 343 matching lines @@
   state->selection_end = range.end();
 
   if (!read_only()) {
     state->set_value_callback =
         base::Bind(&Textfield::AccessibilitySetValue,
                    weak_ptr_factory_.GetWeakPtr());
   }
 }
 
 void Textfield::OnBoundsChanged(const gfx::Rect& previous_bounds) {
-  GetRenderText()->SetDisplayRect(GetContentsBounds());
+  // Allow the text to paint over vertical padding, but not horizontal padding.
+  // kTextPadding was previously unused FocusableBorder inset padding, now that
+  // space is reserved for excessively tall text from unforseen fallback fonts.
+  // This is better than clipping text, shrinking text or painting over borders.

[Peter Kasting, 2014/08/30 00:46:43]

Hmm, I'd really rather not talk about "previously", as over time it becomes more
confusing than meaningful.  How about this comment:

The default kTextPadding value is chosen so there's a reasonable amount of
whitespace on all sides of the user's default font.  Because some fallback fonts
may be taller than the default font, we allow fonts to paint over the vertical
part of this whitespace area.  There are a number of possible alternate
behaviors, such as shrinking fallback fonts more, or dynamically enlarging the
control, but this allows the most reasonable combination of "default font looks
good", "fallback fonts are large enough to be readable", and "controls don't
change size dynamically (surprising users)".

[msw, 2014/09/04 01:25:51]

I revised the comment.

+  gfx::Rect bounds = GetContentsBounds();
+  bounds.Inset(kTextPadding, 0);
+  GetRenderText()->SetDisplayRect(bounds);
   OnCaretBoundsChanged();
 }
 
 void Textfield::OnEnabledChanged() {
   View::OnEnabledChanged();
   if (GetInputMethod())
     GetInputMethod()->OnTextInputTypeChanged(this);
   SchedulePaint();
 }
 
@@ skipping 859 matching lines @@
       const size_t length = selection_clipboard_text.length();
       range = gfx::Range(range.start() + length, range.end() + length);
     }
     model_->MoveCursorTo(gfx::SelectionModel(range, affinity));
     UpdateAfterChange(true, true);
     OnAfterUserAction();
   }
 }
 
 }  // namespace views