Give informative error messages for negative radii in CanvasPathMethods.

Previously these were described with the description of IndexSizeError
in general.

BUG=270033

Review URL: https://codereview.chromium.org/113083005

git-svn-id: svn://svn.chromium.org/blink/trunk@164105 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Structured cloning: improve DataCloneError reporting.

The spec tells us that cloning of neutered objects should throw
DataCloneError:

   http://www.whatwg.org/specs/web-apps/current-work/#safe-passing-of-structured-data

And if an attempt, like in the above, to re-transfer a neutered object
is made, DataCloneError should also be thrown:

  http://www.whatwg.org/specs/web-apps/current-work/#dom-window-postmessage
  http://www.whatwg.org/specs/web-apps/current-work/#dom-messageport-postmessage

The implementation used InvalidStateError instead.

Switch to throwing DataCloneError in SerializedScriptValue, both
during the handling of transferables and the actual cloning step. Hand
in hand with that switch away from the older InvalidStateError,
improve the quality of the error messages that go with the failed
cloning operations. i.e.,

 * SerializedScriptValue::create() now takes an ExceptionState for
   reporting exceptions. This allows context (e.g., what postMessage()
   that is attempting to clone) to be included in the error message.

   (As a result, removed the old method for signalling errors via a
   bool reference.)

 * Rephrase the unmarshalling/extraction of transferable arrays to
   also be reported over an incoming ExceptionState.

 * Make the error messages emitted by MessagePort.postMessage() a
   little bit more consistent.

R=mkwst@chromium.org,dslomov@chromium.org
BUG=327994

Review URL: https://codereview.chromium.org/114363002

git-svn-id: svn://svn.chromium.org/blink/trunk@164106 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Move remaining KeyCode files to platform/

BUG=297477

Review URL: https://codereview.chromium.org/111403004

git-svn-id: svn://svn.chromium.org/blink/trunk@164107 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Implement touch-action pan-x/pan-y handling on the main thread.

This extends the touch-action support on the main thread to handle and combine pan-x and pan-y values appropriately when computing the effective action to send to the embedder.

BUG=321643

Review URL: https://codereview.chromium.org/103823003

git-svn-id: svn://svn.chromium.org/blink/trunk@164108 bbb929c8-8fbe-4397-9dbb-9b2b20218538