Ignores screenshot taking invocations if it's too close to the previous one.

chrome/browser/ui/ash/screenshot_taker.cc

Index: chrome/browser/ui/ash/screenshot_taker.cc
diff --git a/chrome/browser/ui/ash/screenshot_taker.cc b/chrome/browser/ui/ash/screenshot_taker.cc
index 3e9d6556604afb0d6749556cb4303679259d2b64..77de1e72fab4a3b04634ab47b7717b3e0e25fe63 100644
--- a/chrome/browser/ui/ash/screenshot_taker.cc
+++ b/chrome/browser/ui/ash/screenshot_taker.cc
@@ -33,6 +33,8 @@
 #endif
 
 namespace {
+const int kScreenshotMinimumIntervalInMS = 500;
+
 bool ShouldUse24HourClock() {
 #if defined(OS_CHROMEOS)
   Profile* profile = ProfileManager::GetDefaultProfileOrOffTheRecord();
@@ -138,6 +140,10 @@ ScreenshotTaker::ScreenshotTaker() {
 ScreenshotTaker::~ScreenshotTaker() {
 }
 
+void ScreenshotTaker::HandleTakeScreenshot(aura::Window* window) {
+  HandleTakePartialScreenshot(window, window->bounds());
+}
+
 void ScreenshotTaker::HandleTakePartialScreenshot(
     aura::Window* window, const gfx::Rect& rect) {
   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
@@ -164,6 +170,7 @@ void ScreenshotTaker::HandleTakePartialScreenshot(
   bool use_24hour_clock = ShouldUse24HourClock();
 
   if (GrabWindowSnapshot(window, rect, &png_data->data())) {
+    last_screenshot_timestamp_ = base::Time::Now();
     DisplayVisualFeedback(rect);
     content::BrowserThread::PostTask(
         content::BrowserThread::FILE, FROM_HERE,
@@ -174,8 +181,11 @@ void ScreenshotTaker::HandleTakePartialScreenshot(
   }
 }
 
-void ScreenshotTaker::HandleTakeScreenshot(aura::Window* window) {
-  HandleTakePartialScreenshot(window, window->bounds());
+bool ScreenshotTaker::CanTakeScreenshot() {
+  return last_screenshot_timestamp_.is_null() ||
+      base::Time::Now() - last_screenshot_timestamp_ >
+      base::TimeDelta::FromMilliseconds(
+          kScreenshotMinimumIntervalInMS);
 }
 
 void ScreenshotTaker::CloseVisualFeedbackLayer() {