[Mac][MC] Initial accessibility pass.

ui/message_center/cocoa/tray_view_controller.mm

 // Copyright (c) 2013 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.
 
 #import "ui/message_center/cocoa/tray_view_controller.h"
 
 #include <cmath>
 
 #include "base/mac/scoped_nsautorelease_pool.h"
 #include "base/time.h"
@@ skipping 276 matching lines @@
 
   [[self view] addSubview:[settingsController_ view]];
 
   NSRect titleFrame = [title_ frame];
   titleFrame.origin.x =
       NSMaxX([backButton_ frame]) + message_center::kMarginBetweenItems / 2;
   [title_ setFrame:titleFrame];
   [backButton_ setHidden:NO];
   [clearAllButton_ setEnabled:NO];
 
+  [scrollView_ setHidden:YES];
+
   [[[self view] window] recalculateKeyViewLoop];
 
   [self updateTrayViewAndWindow];
 }
 
 - (void)hideSettings:(id)sender {
+  [scrollView_ setHidden:NO];
+
   [[settingsController_ view] removeFromSuperview];
   settingsController_.reset();
 
   NSRect titleFrame = [title_ frame];
   titleFrame.origin.x = NSMinX([backButton_ frame]);
   [title_ setFrame:titleFrame];
   [backButton_ setHidden:YES];
   [clearAllButton_ setEnabled:YES];
 
   [[[self view] window] recalculateKeyViewLoop];
@@ skipping 93 matching lines @@
   [backButton_ setDefaultImage:
       rb.GetNativeImageNamed(IDR_NOTIFICATION_ARROW).ToNSImage()];
   [backButton_ setHoverImage:
       rb.GetNativeImageNamed(IDR_NOTIFICATION_ARROW_HOVER).ToNSImage()];
   [backButton_ setPressedImage:
       rb.GetNativeImageNamed(IDR_NOTIFICATION_ARROW_PRESSED).ToNSImage()];
   [backButton_ setAction:@selector(hideSettings:)];
   configureButton(backButton_);
   [backButton_ setHidden:YES];
   [backButton_ setKeyEquivalent:@"\e"];
+  [backButton_ setToolTip:l10n_util::GetNSString(
+      IDS_MESSAGE_CENTER_SETTINGS_GO_BACK_BUTTON_TOOLTIP)];
+  [[backButton_ cell]
+      accessibilitySetOverrideValue:[backButton_ toolTip]
+                       forAttribute:NSAccessibilityDescriptionAttribute];
   [[self view] addSubview:backButton_];
 
   // Create the divider line between the control area and the notifications.
   scoped_nsobject<NSBox> divider(
       [[NSBox alloc] initWithFrame:NSMakeRect(0, 0, NSWidth([view frame]), 1)]);
   [divider setAutoresizingMask:NSViewMinYMargin];
   [divider setBorderType:NSNoBorder];
   [divider setBoxType:NSBoxCustom];
   [divider setContentViewMargins:NSZeroSize];
   [divider setFillColor:gfx::SkColorToCalibratedNSColor(
@@ skipping 18 matching lines @@
       defaultImage);
   settingsButton_.reset(
       [[HoverImageButton alloc] initWithFrame:settingsButtonFrame]);
   [settingsButton_ setDefaultImage:defaultImage];
   [settingsButton_ setHoverImage:
       rb.GetNativeImageNamed(IDR_NOTIFICATION_SETTINGS_HOVER).ToNSImage()];
   [settingsButton_ setPressedImage:
       rb.GetNativeImageNamed(IDR_NOTIFICATION_SETTINGS_PRESSED).ToNSImage()];
   [settingsButton_ setToolTip:
       l10n_util::GetNSString(IDS_MESSAGE_CENTER_SETTINGS_BUTTON_LABEL)];
+  [[settingsButton_ cell]
+      accessibilitySetOverrideValue:[settingsButton_ toolTip]
+                       forAttribute:NSAccessibilityDescriptionAttribute];
   [settingsButton_ setAction:@selector(showSettings:)];
   configureButton(settingsButton_);
   [view addSubview:settingsButton_];
 
   // Create the clear all button.
   defaultImage = rb.GetNativeImageNamed(IDR_NOTIFICATION_CLEAR_ALL).ToNSImage();
   NSRect clearAllButtonFrame = getButtonFrame(
       NSMinX(settingsButtonFrame) - kButtonXMargin,
       defaultImage);
   clearAllButton_.reset(
       [[HoverImageButton alloc] initWithFrame:clearAllButtonFrame]);
   [clearAllButton_ setDefaultImage:defaultImage];
   [clearAllButton_ setHoverImage:
       rb.GetNativeImageNamed(IDR_NOTIFICATION_CLEAR_ALL_HOVER).ToNSImage()];
   [clearAllButton_ setPressedImage:
       rb.GetNativeImageNamed(IDR_NOTIFICATION_CLEAR_ALL_PRESSED).ToNSImage()];
   [clearAllButton_ setToolTip:
       l10n_util::GetNSString(IDS_MESSAGE_CENTER_CLEAR_ALL)];
+  [[clearAllButton_ cell]
+      accessibilitySetOverrideValue:[clearAllButton_ toolTip]
+                       forAttribute:NSAccessibilityDescriptionAttribute];
   [clearAllButton_ setAction:@selector(clearAllNotifications:)];
   configureButton(clearAllButton_);
   [view addSubview:clearAllButton_];
 
   // Create the pause button.
   defaultImage = rb.GetNativeImageNamed(IDR_NOTIFICATION_PAUSE).ToNSImage();
   NSRect pauseButtonFrame = getButtonFrame(
       NSMinX(clearAllButtonFrame) - kButtonXMargin,
       defaultImage);
   pauseButton_.reset([[HoverImageButton alloc] initWithFrame:pauseButtonFrame]);
   [pauseButton_ setDefaultImage:defaultImage];
   [pauseButton_ setHoverImage:
       rb.GetNativeImageNamed(IDR_NOTIFICATION_PAUSE_HOVER).ToNSImage()];
   [pauseButton_ setPressedImage:
       rb.GetNativeImageNamed(IDR_NOTIFICATION_PAUSE_PRESSED).ToNSImage()];
   [pauseButton_ setToolTip:
       l10n_util::GetNSString(IDS_MESSAGE_CENTER_QUIET_MODE_BUTTON_TOOLTIP)];
+  [[pauseButton_ cell]
+      accessibilitySetOverrideValue:[pauseButton_ toolTip]
+                       forAttribute:NSAccessibilityDescriptionAttribute];
   [pauseButton_ setAction:@selector(toggleQuietMode:)];
   configureButton(pauseButton_);
   [view addSubview:pauseButton_];
 }
 
 - (void)updateTrayViewAndWindow {
   CGFloat scrollContentHeight = 0;
   if ([notifications_ count]) {
     scrollContentHeight = NSMaxY([[[notifications_ lastObject] view] frame]) +
         message_center::kMarginBetweenItems;;
@@ skipping 212 matching lines @@
 
   [pauseButton_ setEnabled:YES];
   [clearAllButton_ setEnabled:YES];
   [settingsButton_ setEnabled:YES];
   [clipView_ setFrozen:NO];
 
   messageCenter_->RemoveAllNotifications(true);
 }
 
 @end