Suspend shared timers while blockingly closing databases

BUG=388771
R=michaeln@chromium.org

Review URL: https://codereview.chromium.org/409863002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@284785 0039d316-1c4b-4281-b951-d872f2087c98
void RenderThreadImpl::HistogramCustomizer::SetCommonHost(
    const std::string& host) {
  if (host != common_host_) {
    common_host_ = host;
    common_host_histogram_suffix_ = HostToCustomHistogramSuffix(host);
    blink::mainThreadIsolate()->SetCreateHistogramFunction(CreateHistogram);
  }
}

void RenderThreadImpl::HistogramCustomizer::SetCommonHost(
    const std::string& host) {
  if (host != common_host_) {
    common_host_ = host;
    common_host_histogram_suffix_ = HostToCustomHistogramSuffix(host);
    blink::mainThreadIsolate()->SetCreateHistogramFunction(CreateHistogram);
  }
}
