[RenderText] Adding vertical alignment options

ui/gfx/canvas.h

 // 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.
 
 #ifndef UI_GFX_CANVAS_H_
 #define UI_GFX_CANVAS_H_
 
 #include <vector>
 
 #include "base/basictypes.h"
@@ skipping 51 matching lines @@
     NO_ELLIPSIS = 1 << 7,
 
     // Specifies if words can be split by new lines.
     // This only works with MULTI_LINE.
     CHARACTER_BREAK = 1 << 8,
 
     // Instructs DrawStringRect() to not use subpixel rendering.  This is useful
     // when rendering text onto a fully- or partially-transparent background
     // that will later be blended with another image.
     NO_SUBPIXEL_RENDERING = 1 << 9,
+
+    // Specifies the alignment for text rendered with the DrawStringRect method.

[msw, 2015/04/01 15:07:17]

Let's not add these flags unless they are imminently needed (I hope we can
deprecate the canvas string drawing functions eventually).

+    TEXT_ALIGN_TOP = 1 << 10,
+    TEXT_ALIGN_MIDDLE = 1 << 11,
+    TEXT_ALIGN_BOTTOM = 1 << 12,
   };
 
   // Creates an empty canvas with image_scale of 1x.
   Canvas();
 
   // Creates canvas with provided DIP |size| and |image_scale|.
   // If this canvas is not opaque, it's explicitly cleared to transparent before
   // being returned.
   Canvas(const Size& size, float image_scale, bool is_opaque);
 
@@ skipping 361 matching lines @@
 
   skia::RefPtr<skia::PlatformCanvas> owned_canvas_;
   SkCanvas* canvas_;
 
   DISALLOW_COPY_AND_ASSIGN(Canvas);
 };
 
 }  // namespace gfx
 
 #endif  // UI_GFX_CANVAS_H_