Make 'Bookmark all tabs' window able to minimize upto default size.

Currently 'Bookmark all tabs' and 'Bookmark Edit' window have different minimum and default sizes. Make them consistent.

XIB Changes:
BookmarkAllTabs & Bookmark Editor window's minimum and default sizes are set in .xib file located at
chrome/app/nibs/BookmarkAllTabs.xib
chrome/app/nibs/BookmarkEditor.xib

Their window's default and minimum width and height values are decided by NSWindowRect & NSWindowContentMinSize key strings repectively. Set the correct values such that BookmarkAllTabs & Bookmark Editor windows are consistent

BUG=401491
R=asvitkine@chromium.org

TEST=
1) Launch chrome, open 2-3 tabs, right click on last tab and select 'Bookmark all tabs'.
2) On opened window increase the size by dragging towards R.H.S, and then try to decrease the size by dragging towards L.H.S and Observe.
3) The bookmark window should be minimize upto default size as of "Bookmark Edit" window.

Review URL: https://codereview.chromium.org/537553002

Cr-Commit-Position: refs/heads/master@{#294338}

chrome/app/nibs/BookmarkAllTabs.xib

@@ -49,13 +49,13 @@
 			<object class="NSWindowTemplate" id="1005">
 				<int key="NSWindowStyleMask">9</int>
 				<int key="NSWindowBacking">2</int>
-				<string key="NSWindowRect">{{196, 242}, {480, 268}}</string>
+				<string key="NSWindowRect">{{196, 240}, {580, 270}}</string>
 				<int key="NSWTFlags">536870912</int>
 				<string key="NSWindowTitle">Bookmark All Tabs</string>
 				<string key="NSWindowClass">NSWindow</string>
 				<nil key="NSViewClass"/>
 				<nil key="NSUserInterfaceItemIdentifier"/>
-				<string key="NSWindowContentMinSize">{480, 244}</string>
+				<string key="NSWindowContentMinSize">{331, 270}</string>
 				<object class="NSView" key="NSWindowView" id="1006">
 					<reference key="NSNextResponder"/>
 					<int key="NSvFlags">256</int>