[Android] Added a runtime flag to enable autoplay of muted videos.

third_party/WebKit/Source/core/html/HTMLMediaElement.cpp

Index: third_party/WebKit/Source/core/html/HTMLMediaElement.cpp
diff --git a/third_party/WebKit/Source/core/html/HTMLMediaElement.cpp b/third_party/WebKit/Source/core/html/HTMLMediaElement.cpp
index 7beecb9dd4be9a28665ac847fe9e6f45f67b085f..48ac87082a865889a7cb762c0b8c884fa9adde03 100644
--- a/third_party/WebKit/Source/core/html/HTMLMediaElement.cpp
+++ b/third_party/WebKit/Source/core/html/HTMLMediaElement.cpp
@@ -3659,10 +3659,18 @@ void HTMLMediaElement::unlockUserGesture()
     m_lockedPendingUserGesture = false;
 }
 
-bool HTMLMediaElement::isGestureNeededForPlayback() const
+bool HTMLMediaElement::isGestureNeededForPlayback()
 {
-    return m_lockedPendingUserGesture
-        && !m_autoplayHelper->isGestureRequirementOverridden();
+    if (!m_lockedPendingUserGesture)
+        return false;
+
+    if (muted() && RuntimeEnabledFeatures::videosAsImagesEnabled())
+        return false;
+
+    if (m_autoplayHelper->isGestureRequirementOverridden())
+        return false;
+
+    return true;
 }
 
 void HTMLMediaElement::setNetworkState(NetworkState state)