DevTools: Track async stacks on the corresponding execution context.

We should track async stacks separately for each execution context,
so that async event IDs (like timer ID) from different execution
contexts (e.g. iframes) should not mess with each other.

BUG=272416
R=yurys, pfeldman

Review URL: https://codereview.chromium.org/111653002

git-svn-id: svn://svn.chromium.org/blink/trunk@163553 bbb929c8-8fbe-4397-9dbb-9b2b20218538
DevTools: Remove unneeded didReceiveXHRResponse instrumentation.

This method was used to detect the type of synchronous XHR requests.
Now that synchronous XHRs use RawResource for loading it is no longer needed.

R=pfeldman, caseq

Review URL: https://codereview.chromium.org/106663005

git-svn-id: svn://svn.chromium.org/blink/trunk@163554 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Disable BitmapImageTests on Windows

They always fail on the WebKit XP (deps) bots. Disabling them, at least temporarily,
to see if the failures might move to other tests.

BUG=327104
TBR=wangxianzhu@chromium.org

Review URL: https://codereview.chromium.org/111443003

git-svn-id: svn://svn.chromium.org/blink/trunk@163555 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Editing - Code refactoring to avoid redundant function calls

Minor cleanup that I came across while working on other issues, to knock off redundant fucntion calls.
Also got rid of an unused variable.

TEST=No tests added since this is a refactoring.

Review URL: https://codereview.chromium.org/105483003

git-svn-id: svn://svn.chromium.org/blink/trunk@163556 bbb929c8-8fbe-4397-9dbb-9b2b20218538
DevTools: collect GPU memory usage

Collect used GPU memory and display it on the Counters pane
in timeline memory view.

BUG=326497

Review URL: https://codereview.chromium.org/108223002

git-svn-id: svn://svn.chromium.org/blink/trunk@163557 bbb929c8-8fbe-4397-9dbb-9b2b20218538