telemetry: replace Google drive by image search in top_25 page set.

tools/perf/page_sets/top_25.json

 {
   "description": "Pages hand-picked for 2012 CrOS scrolling tuning efforts.",
   "archive_data_file": "data/top_25.json",
   "credentials_path": "data/credentials.json",
   "user_agent_type": "desktop",
   "smoothness": { "action": "scroll" },
   "pages": [
     {
       "url": "https://www.google.com/#hl=en&q=barack+obama",
       "why": "top google property; a google tab is often open",
@@ skipping 86 matching lines @@
         { "action": "wait", "condition": "element", "selector": "div[class~=\"navBack\"]" },
         { "action": "click_element", "selector": "div[class~=\"navBack\"]" },
         { "action": "wait", "seconds": 2 },
         { "action": "wait", "condition": "element", "selector": "div[class~=\"navBack\"]" },
         { "action": "click_element", "selector": "div[class~=\"navBack\"]" },
         { "action": "wait", "seconds": 2 },
         { "action": "wait", "condition": "element", "selector": "div[class~=\"navBack\"]" }
       ]
     },
     {
-      "url": "https://drive.google.com",
-      "why": "productivity, top google properties",
-      "credentials": "google",
-      "navigate_steps" : [
-        { "action": "navigate" },
-        { "action": "wait", "javascript": "document.getElementsByClassName('doclistview-list').length" }
-      ],
-      "smoothness": {
-        "action": "scroll",
-        "scrollable_element_function": "function(callback) { callback(document.getElementsByClassName('doclistview-list')[0]); }"
-      }
+      "url": "https://www.google.com/search?q=cats&tbm=isch",
+      "why": "tough image case; top google properties",
+      "credentials": "google"
     },
     {
       "name": "Docs  (1 open document tab)",
       "url": "https://docs.google.com/document/d/1X-IKNjtEnx-WW5JIKRLsyhz5sbsat3mfTpAPUSX3_s4/view",
       "why": "productivity, top google properties; Sample doc in the link",
       "credentials": "google",
       "navigate_steps" : [
         { "action": "navigate" },
         { "action": "wait", "seconds": 2 },
         { "action": "wait", "javascript": "document.getElementsByClassName('kix-appview-editor').length" }
@@ skipping 205 matching lines @@
     {
       "url": "http://sports.yahoo.com/",
       "why": "#1 Alexa sports"
     },
     {
       "url": "http://techcrunch.com",
       "why": "top tech blog"
     }
   ]
 }