Don't spam the GPU process with memory usage stats

cc/layer_tree_host_impl.cc

Index: cc/layer_tree_host_impl.cc
diff --git a/cc/layer_tree_host_impl.cc b/cc/layer_tree_host_impl.cc
index 8f32526fbc635f0ef6ac3375c45755e1b89b4618..4f636a21479e796e838424664398df1f327d1ea7 100644
--- a/cc/layer_tree_host_impl.cc
+++ b/cc/layer_tree_host_impl.cc
@@ -32,6 +32,7 @@
 #include "cc/software_renderer.h"
 #include "cc/solid_color_draw_quad.h"
 #include "cc/texture_uploader.h"
+#include "cc/util.h"
 #include "ui/gfx/size_conversions.h"
 #include "ui/gfx/vector2d_conversions.h"
 
@@ -227,6 +228,9 @@ LayerTreeHostImpl::LayerTreeHostImpl(const LayerTreeSettings& settings, LayerTre
     , m_numImplThreadScrolls(0)
     , m_numMainThreadScrolls(0)
     , m_cumulativeNumLayersDrawn(0)
+    , m_lastSentMemoryVisibleBytes(0)
+    , m_lastSentMemoryVisibleAndNearbyBytes(0)
+    , m_lastSentMemoryUseBytes(0)
 {
     DCHECK(m_proxy->isImplThread());
     didVisibilityChange(this, m_visible);
@@ -1619,6 +1623,34 @@ void LayerTreeHostImpl::renderingStats(RenderingStats* stats) const
         m_tileManager->renderingStats(stats);
 }
 
+void LayerTreeHostImpl::sendManagedMemoryStats(
+    size_t memoryVisibleBytes,
+    size_t memoryVisibleAndNearbyBytes,
+    size_t memoryUseBytes)
+{
+    if (!renderer())
+      return;
+
+    // Round the numbers being sent up to the next 8MB, to throttle the rate
+    // at which we spam the GPU process.
+    const size_t roundingStep = 8 * 1024 * 1024;

[jamesr, 2012/12/07 23:19:12]

nit: "static const ...", so you don't get another copy on the stack every time
you call this

[ccameron, 2012/12/08 00:21:15]

Done.

+    memoryVisibleBytes = RoundUp(memoryVisibleBytes, roundingStep);
+    memoryVisibleAndNearbyBytes = RoundUp(memoryVisibleAndNearbyBytes, roundingStep);
+    memoryUseBytes = RoundUp(memoryUseBytes, roundingStep);
+    if (m_lastSentMemoryVisibleBytes == memoryVisibleBytes &&
+        m_lastSentMemoryVisibleAndNearbyBytes == memoryVisibleAndNearbyBytes &&
+        m_lastSentMemoryUseBytes == memoryUseBytes) {
+        return;
+    }
+    m_lastSentMemoryVisibleBytes = memoryVisibleBytes;
+    m_lastSentMemoryVisibleAndNearbyBytes = memoryVisibleAndNearbyBytes;
+    m_lastSentMemoryUseBytes = memoryUseBytes;
+
+    renderer()->sendManagedMemoryStats(m_lastSentMemoryVisibleBytes,
+                                       m_lastSentMemoryVisibleAndNearbyBytes,
+                                       m_lastSentMemoryUseBytes);
+}
+
 void LayerTreeHostImpl::animateScrollbars(base::TimeTicks time)
 {
     animateScrollbarsRecursive(m_rootLayerImpl.get(), time);