Update image content rect on src changes even if intrinsic size matches

Update image content rect on src changes even if intrinsic size matches

This patch changes RenderImage::imageDimensionsChanged to update the
image content rect even if the image's intrinsic size is equal. This
fixes a bug where changing an SVG image to another image of the same
size would not correctly update the image content rect.

This patch also cleans up a confusing variable name in
RenderImage::updateInnerContentRect, changing paint rect to container
rect to better match what it is.

BUG=269946
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=158343

[f(malita), 2013-09-25 19:47:25]

lgtm

[commit-bot: I haz the power, 2013-09-25 19:47:39]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/pdr@chromium.org/23890043/1

[commit-bot: I haz the power, 2013-09-26 00:52:02]

Change committed as 158343