Clean up safe_browsing_util.h operator overloads.

Remove the SBFullHash operator overloads, and provide a common function
to turn a std::string into an SBFullHash.

BUG=none

Review URL: https://codereview.chromium.org/197023011

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@256785 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 256785
Clean-up: Fix FrameInput::InsertAudio() interface, and remove ref-counting of AudioEncoder.

1. Rather than pass a done callback around, explicitly pass ownership of each AudioBus to the InsertAudio() calls.

2. AudioEncoder is no longer ref-counted.  Instead, its inner "impl class" is ref-counted since it can be referenced by two threads (MAIN and AUDIO_ENCODER).

BUG=344628

Review URL: https://codereview.chromium.org/198333002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@256786 0039d316-1c4b-4281-b951-d872f2087c98
Remove some content_child dependency from content_common

content_common does not have an explicit dependency on content_child in the GYP
files, yet depends on symbols from content_child.  This causes order-dependent
linker errors on some builds (e.g. win8_aura).  Fix this by refactoring
content::ChildThread to remove the need for that dependency, namely:

* Refactor content::ChildThread to allow users to access (and pass around) its
  content::MessageRouter member for use in IPC messaging, instead of passing
  around the ChildThread itself.
* Remove explicit check for ChildThread in content::VaapiVideoDecodeAccelerator.
* Update DEPS files accordingly.

BUG=351948
TEST=local build on desktop Linux

Review URL: https://codereview.chromium.org/198073003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@256787 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 256787