Code: void AwContents::UpdateScrollState(gfx::Vector2d max_scroll_offset,
                                   gfx::SizeF contents_size_dip,
                                    float page_scale_factor,
                                    float min_page_scale_factor,
                                    float max_page_scale_factor) {
  DCHECK_CURRENTLY_ON(BrowserThread::UI);
  JNIEnv* env = AttachCurrentThread();
  ScopedJavaLocalRef<jobject> obj = java_ref_.get(env);
  if (obj.is_null())
    return;
  Java_AwContents_updateScrollState(env,
                                    obj.obj(),
                                    max_scroll_offset.x(),
                                    max_scroll_offset.y(),
                                    contents_size_dip.width(),
                                    contents_size_dip.height(),
                                    page_scale_factor,
                                    min_page_scale_factor,
                                     max_page_scale_factor);
 }

Vulnerability Type: DoS 
CWE ID: CWE-399
Summary: Use-after-free vulnerability in the StyleElement::removedFromDocument function in core/dom/StyleElement.cpp in Blink, as used in Google Chrome before 35.0.1916.114, allows remote attackers to cause a denial of service (application crash) or possibly have unspecified other impact via crafted JavaScript code that triggers tree mutation.
Commit Message: sync compositor: pass simple gfx types by const ref

See bug for reasoning

BUG=159273

Review URL: https://codereview.chromium.org/1417893006

Cr-Commit-Position: refs/heads/master@{#356653}