Address views session crashed bubble style nits.

Use the built-in bubble title and close button views.
Use the bubble's title insets for the other views.
Use BookmarkSyncPromoView colors for the UMA promo.
Use views layout constants for the spacing values.
Use default label/checkbox/bubble colors, not hard-coded.
(black/off-white + supports inversion for accessibility)
Fix the UMA promo separator line (wasn't fully extended).

Inline some BrowserRemovalObserver function implementations.
Other misc. code cleanup. See before/after pics on the bug.

BUG=384123
TEST=Session crashes bubble looks good, works well.
R=yiyaoliu@chromium.org,sky@chromium.org

Review URL: https://codereview.chromium.org/331353002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@278228 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/ui/views/session_crashed_bubble_view.h

@@ -60,6 +60,9 @@ class SessionCrashedBubbleView
 
   // WidgetDelegateView methods.
   virtual views::View* GetInitiallyFocusedView() OVERRIDE;
+  virtual base::string16 GetWindowTitle() const OVERRIDE;
+  virtual bool ShouldShowWindowTitle() const OVERRIDE;
+  virtual bool ShouldShowCloseButton() const OVERRIDE;
 
   // views::BubbleDelegateView methods.
   virtual void Init() OVERRIDE;
@@ -118,9 +121,6 @@ class SessionCrashedBubbleView
   // Button for the user to confirm a session restore.
   views::LabelButton* restore_button_;
 
-  // Button for the user to close this bubble.
-  views::LabelButton* close_;
-
   // Checkbox for the user to opt-in to UMA reporting.
   views::Checkbox* uma_option_;