Fix for Left mouse drag which was not functional  after right drag in DoubleSplitViewExample.
Fix for Left mouse drag which was not functional  after right drag in DoubleSplitViewExample.

  SplittedView::GetPreferredSize() was returning it's own size,instead of preferred size. Hence new_size was always = divder_offset_ in SingleSplitView::OnMosueDrag(), leading to no Layout() call.

  Avoid overriding SplittedView ::GetPreferredSize() to use default implementation.



BUG=none
TEST=Drag second splitter from left to right and then drag same splitter to right


Review URL: http://codereview.chromium.org/7998001

git-svn-id: de016e52bd170d2d4f2344f9bf92d50478b649e0@102479 0039d316-1c4b-4281-b951-d872f2087c98

gavinp/chromium,adobe/chromium,ropik/chromium,adobe/chromium,ropik/chromium,yitian134/chromium,yitian134/chromium,yitian134/chromium,yitian134/chromium,adobe/chromium,gavinp/chromium,yitian134/chromium,adobe/chromium,ropik/chromium,yitian134/chromium,ropik/chromium,adobe/chromium,gavinp/chromium,adobe/chromium,ropik/chromium,adobe/chromium,gavinp/chromium,gavinp/chromium,gavinp/chromium,gavinp/chromium,adobe/chromium,yitian134/chromium,yitian134/chromium,ropik/chromium,ropik/chromium,ropik/chromium,gavinp/chromium,ropik/chromium,adobe/chromium,yitian134/chromium,adobe/chromium,adobe/chromium,yitian134/chromium,gavinp/chromium,gavinp/chromium