Fix exception on navigation while "Recoding object allocations"

Current profile may have been removed by the time didTakeHeapSnapshot is invoked.

BUG=None
R=alph@chromium.org

Review URL: https://codereview.chromium.org/167003006

git-svn-id: svn://svn.chromium.org/blink/trunk@167336 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Improve MediaSource exception messages.

BUG=270033

Review URL: https://codereview.chromium.org/169623005

git-svn-id: svn://svn.chromium.org/blink/trunk@167337 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Remove WrapperWorldType from DOMDataStore

I'm removing WrapperWorldType from the code base.
What DOMDataStore needs to know is just whether we're in the main world or not.
Thus this CL replaces WrapperWorldType with 'bool m_isMainWorld'.

BUG=341032

Review URL: https://codereview.chromium.org/163913005

git-svn-id: svn://svn.chromium.org/blink/trunk@167338 bbb929c8-8fbe-4397-9dbb-9b2b20218538
[oilpan] Fix NeedsTracing trait for heap collections nested in other collections

R=ager@chromium.org, haraken@chromium.org, vegorov@chromium.org
BUG=

Review URL: https://codereview.chromium.org/170433002

git-svn-id: svn://svn.chromium.org/blink/trunk@167339 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Improve NavigatorMediaStream exception messages.

BUG=270033

Review URL: https://codereview.chromium.org/170163005

git-svn-id: svn://svn.chromium.org/blink/trunk@167340 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Oilpan: Move RBGColor to the oilpan heap using transition types.

R=haraken@chromium.org, wibling@chromium.org
BUG=

Review URL: https://codereview.chromium.org/170163007

git-svn-id: svn://svn.chromium.org/blink/trunk@167341 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Fixed visible contents size calculation under scale with scrollbars.

The visible contents rects calculated in FrameView didn't account
properly for scrollbars when scaled. With the desktop pinch we need
to include the fact that scrollbars will scale along with the page.
This patch changes the visibleContentsRect method to subtract the
scrollbar thickness only after converting to CSS pixels.

Additionally, WebViewImpl's method to clamp scroll offset at a
certain scale also did not account for scaled scrollbars.

BUG=336539

Review URL: https://codereview.chromium.org/151453003

git-svn-id: svn://svn.chromium.org/blink/trunk@167342 bbb929c8-8fbe-4397-9dbb-9b2b20218538