STORM-1028 WIP Fixed chat bar occupying all available space on first login.

1. Make sure we initialize desired chat bar width before using it.
2. Don't attempt shrinking chat bar by negative amount of pixels
   (i.e. effectively extending it). This change may be irrelevant
   to the bug I'm fixing, but won't hurt anyway.

indra/newview/llbottomtray.cpp

@@ -201,7 +201,8 @@ public:
 };
 
 LLBottomTray::LLBottomTray(const LLSD&)
-:	mChicletPanel(NULL),
+:	mDesiredNearbyChatWidth(0),
+	mChicletPanel(NULL),
 	mSpeakPanel(NULL),
 	mSpeakBtn(NULL),
 	mNearbyChatBar(NULL),
@@ -1095,7 +1096,9 @@ S32 LLBottomTray::processWidthDecreased(S32 delta_width)
 	if (still_should_be_processed)
 	{
 		processShrinkButtons(delta_width, buttons_freed_width);
+		still_should_be_processed = delta_width < 0;
 	}
+
 	// 3. Decreasing width of nearby chat.
 	const S32 chatbar_panel_min_width = get_panel_min_width(mToolbarStack, mChatBarContainer);
 	const S32 chatbar_panel_width = mChatBarContainer->getRect().getWidth();