Uninstall themes when all theme infobars are gone; not on each infobar's destruction.

There are multiple problems with the current implementation:
- It handles multiple tabs with theme install infobars badly.
- It has a subtle race condition where installing a second theme, and then
  installing the original theme (note: not clicking undo) uninstalled both
  themes.

Instead, only uninstall unused themes when all infobars are closed down.

BUG=none
TEST=Install theme A. Install theme B. Install theme A. Restart chrome. Theme A should show.
TEST=Install theme A in window 1. Install theme B in window 2. Install theme C in window 3. Clicking undo in any of those windows in any order should work.

Review URL: http://codereview.chromium.org/504052

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@34890 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 11 insertions, 0 deletions

diff --git a/chrome/browser/browser_theme_provider.h b/chrome/browser/browser_theme_provider.h
index e6275d6..756e2bc 100644
--- a/chrome/browser/browser_theme_provider.h
+++ b/chrome/browser/browser_theme_provider.h
@@ -129,6 +129,14 @@ class BrowserThemeProvider : public NonThreadSafe,
   // locally customized.)
   std::string GetThemeID() const;
 
+  // This class needs to keep track of the number of theme infobars so that we
+  // clean up unused themes.
+  void OnInfobarDisplayed();
+
+  // Decrements the number of theme infobars. If the last infobar has been
+  // destroyed, uninstalls all themes that aren't the currently selected.
+  void OnInfobarDestroyed();
+
   // Convert a bitfield alignment into a string like "top left". Public so that
   // it can be used to generate CSS values. Takes a bitfield of AlignmentMasks.
   static std::string AlignmentToString(int alignment);
@@ -215,6 +223,9 @@ class BrowserThemeProvider : public NonThreadSafe,
 
   scoped_refptr<BrowserThemePack> theme_pack_;
 
+  // The number of infobars currently displayed.
+  int number_of_infobars_;
+
   DISALLOW_COPY_AND_ASSIGN(BrowserThemeProvider);
 };